We present a study of six dusty and gaseous pillars (containing the HH 1004 and HH 1010 objects)
and globules (that contain the HH 666, HH 900, HH 1006, and HH 1066 objects) localized in the Carina
nebula using sensitive and high angular resolution (∼0.3′′) Atacama Large Millimeter/Sub-millimeter
Array (ALMA) observations. This is a more extensive study that the one presented in Cortes-Rangel
et al. (2020). As in this former study, we also analyzed the 1.3 mm continuum emission and C18O(2−1),
N2D+(3−2) and 12CO(2−1) spectral lines. These new observations revealed the molecular outflows
emanating from the pillars, the dusty envelopes+disks that are exciting them, and the extended HH
objects far from their respective pillars. We reveal that the masses of the disks+envelopes are in a
range of 0.02 to 0.38 M⊙, and those for the molecular outflows are of the order of 10−3 M⊙, which
suggests that their exciting sources might be low- or intermediate-mass protostars as already revealed
in recent studies at infrared and submillimeter bands. In the regions associated with the objects HH
900 and HH 1004, we report multiple millimeter continuum sources, from where several molecular
outflows emanate.
The canarias einstein_ring_a_newly_discovered_optical_einstein_ringSérgio Sacani
This document reports the discovery of a newly discovered optical Einstein ring (ER) called the "Canarias Einstein Ring". It was discovered serendipitously in imaging data from the Dark Energy Camera. Follow-up spectroscopy with the Gran Telescopio CANARIAS confirmed the nature of the system, with the lens being an early-type galaxy at a redshift of z=0.581 and the source being a starburst galaxy at z=1.165. Analysis of the system determined the Einstein radius to be 2.16 arcseconds and the total enclosed mass producing the lensing effect to be 1.86 ± 0.23 × 1012 solar masses.
Alma observations of_the_hh46_47_molecular_outflowSérgio Sacani
ALMA observations of the HH 46/47 molecular outflow reveal striking differences between the blue and red lobes. The blue lobe morphology and kinematics are consistent with entrainment by a wide-angle wind, while the red lobe shows a more complex structure with evidence of entrainment by both a wide-angle wind and collimated episodic winds. Three major clumps along the red lobe axis have velocity distributions consistent with prompt entrainment by periodic mass ejection episodes occurring every few hundred years. Position-velocity cuts show velocity gradients increasing toward the outflow axis, inconsistent with outflow rotation.
Solving the Multimessenger Puzzle of the AGN-starburst Composite Galaxy NGC 1068Sérgio Sacani
Multiwavelength observations indicate that some starburst galaxies show a dominant nonthermal contribution from
their central region. These active galactic nuclei (AGN)-starburst composites are of special interest, as both
phenomena on their own are potential sources of highly energetic cosmic rays and associated γ-ray and neutrino
emission. In this work, a homogeneous, steady-state two-zone multimessenger model of the nonthermal emission
from the AGN corona as well as the circumnuclear starburst region is developed and subsequently applied to the
case of NGC 1068, which has recently shown some first indications of high-energy neutrino emission. Here, we
show that the entire spectrum of multimessenger data—from radio to γ-rays including the neutrino constraint—can
be described very well if both, starburst and AGN corona, are taken into account. Using only a single emission
region is not sufficient.
MUSE sneaks a peek at extreme ram-pressure stripping events. I. A kinematic s...Sérgio Sacani
- MUSE observations of the galaxy ESO137-001 reveal an extended gaseous tail over 30 kpc long traced by H-alpha emission, providing evidence of an extreme ram pressure stripping event as the galaxy falls into the massive Norma galaxy cluster.
- Analysis of the H-alpha kinematics and stellar velocity field show that ram pressure has removed the interstellar medium from the outer disk while the primary tail is still fed by gas from the galaxy center, with gravitational interactions not appearing to be the main mechanism of gas removal.
- The stripped gas retains evidence of the disk's rotational velocity out to around 20 kpc downstream, indicating the galaxy is moving radially along the plane of the sky, while
This document describes observations of the galaxy ESO137-001 using the MUSE instrument on the VLT. The key points are:
1) MUSE observations reveal an extended gas tail stretching over 30 kpc from the galaxy, tracing ongoing ram pressure stripping as it falls into the Norma galaxy cluster.
2) Analysis of the gas kinematics and stellar velocity field show that ram pressure has removed the interstellar medium from the outer disk while the primary tail is still fed by gas from the galaxy center.
3) The stripped gas retains evidence of the disk's rotational velocity out to 20 kpc downstream, indicating the galaxy is moving radially through the cluster. Beyond this the gas shows greater turbulence,
Dust in the_polar_region_as_a_major_contributor_to_the_infrared_emission_of_a...Sérgio Sacani
The mid-infrared emission of the active galactic nucleus NGC 3783 was observed using interferometry over multiple epochs, providing dense coverage of position angles and baselines. The emission was found to be strongly elongated along a position angle of -52 degrees, closely aligned with the polar axis orientation of -45 degrees. The half-light radii were measured to be 20.0 mas by 6.7 mas, corresponding to an axis ratio of 3:1. This implies that 60-90% of the 8-13 micron emission is from the polar-elongated component. The observations support a scenario where the majority of mid-infrared emission in Seyfert galaxies originates from a dusty wind in the polar region,
The ASTRODEEP Frontier Fields catalogues II. Photometric redshifts and rest f...Sérgio Sacani
This document describes a public release of photometric redshifts and galaxy properties from multi-wavelength data in the Abell-2744 and MACS-J0416 galaxy cluster fields observed as part of the Frontier Fields program. Photometric redshifts were estimated using six different methods and have an accuracy of 3-5%. Accounting for gravitational lensing magnification, the H-band number counts agree with CANDELS at bright magnitudes but extend to intrinsically fainter galaxies of H=32-33. The Frontier Fields data allow probing galaxy stellar masses 0.5-1.5 dex lower than in wide fields, including sources with masses of 107-108 solar masses at z>5. Star formation rates can be detected 1
Exocometary gas in_th_hd_181327_debris_ringSérgio Sacani
An increasing number of observations have shown that gaseous debris discs are not an
exception. However, until now we only knew of cases around A stars. Here we present the first
detection of 12CO (2-1) disc emission around an F star, HD 181327, obtained with ALMA
observations at 1.3 mm. The continuum and CO emission are resolved into an axisymmetric
disc with ring-like morphology. Using a Markov chain Monte Carlo method coupled with
radiative transfer calculations we study the dust and CO mass distribution. We find the dust is
distributed in a ring with a radius of 86:0 0:4 AU and a radial width of 23:2 1:0 AU. At
this frequency the ring radius is smaller than in the optical, revealing grain size segregation
expected due to radiation pressure. We also report on the detection of low level continuum
emission beyond the main ring out to 200 AU. We model the CO emission in the non-LTE
regime and we find that the CO is co-located with the dust, with a total CO gas mass ranging
between 1:2 10 6 M and 2:9 10 6 M, depending on the gas kinetic temperature and
collisional partners densities. The CO densities and location suggest a secondary origin, i.e.
released from icy planetesimals in the ring. We derive a CO cometary composition that is
consistent with Solar system comets. Due to the low gas densities it is unlikely that the gas is
shaping the dust distribution.
The canarias einstein_ring_a_newly_discovered_optical_einstein_ringSérgio Sacani
This document reports the discovery of a newly discovered optical Einstein ring (ER) called the "Canarias Einstein Ring". It was discovered serendipitously in imaging data from the Dark Energy Camera. Follow-up spectroscopy with the Gran Telescopio CANARIAS confirmed the nature of the system, with the lens being an early-type galaxy at a redshift of z=0.581 and the source being a starburst galaxy at z=1.165. Analysis of the system determined the Einstein radius to be 2.16 arcseconds and the total enclosed mass producing the lensing effect to be 1.86 ± 0.23 × 1012 solar masses.
Alma observations of_the_hh46_47_molecular_outflowSérgio Sacani
ALMA observations of the HH 46/47 molecular outflow reveal striking differences between the blue and red lobes. The blue lobe morphology and kinematics are consistent with entrainment by a wide-angle wind, while the red lobe shows a more complex structure with evidence of entrainment by both a wide-angle wind and collimated episodic winds. Three major clumps along the red lobe axis have velocity distributions consistent with prompt entrainment by periodic mass ejection episodes occurring every few hundred years. Position-velocity cuts show velocity gradients increasing toward the outflow axis, inconsistent with outflow rotation.
Solving the Multimessenger Puzzle of the AGN-starburst Composite Galaxy NGC 1068Sérgio Sacani
Multiwavelength observations indicate that some starburst galaxies show a dominant nonthermal contribution from
their central region. These active galactic nuclei (AGN)-starburst composites are of special interest, as both
phenomena on their own are potential sources of highly energetic cosmic rays and associated γ-ray and neutrino
emission. In this work, a homogeneous, steady-state two-zone multimessenger model of the nonthermal emission
from the AGN corona as well as the circumnuclear starburst region is developed and subsequently applied to the
case of NGC 1068, which has recently shown some first indications of high-energy neutrino emission. Here, we
show that the entire spectrum of multimessenger data—from radio to γ-rays including the neutrino constraint—can
be described very well if both, starburst and AGN corona, are taken into account. Using only a single emission
region is not sufficient.
MUSE sneaks a peek at extreme ram-pressure stripping events. I. A kinematic s...Sérgio Sacani
- MUSE observations of the galaxy ESO137-001 reveal an extended gaseous tail over 30 kpc long traced by H-alpha emission, providing evidence of an extreme ram pressure stripping event as the galaxy falls into the massive Norma galaxy cluster.
- Analysis of the H-alpha kinematics and stellar velocity field show that ram pressure has removed the interstellar medium from the outer disk while the primary tail is still fed by gas from the galaxy center, with gravitational interactions not appearing to be the main mechanism of gas removal.
- The stripped gas retains evidence of the disk's rotational velocity out to around 20 kpc downstream, indicating the galaxy is moving radially along the plane of the sky, while
This document describes observations of the galaxy ESO137-001 using the MUSE instrument on the VLT. The key points are:
1) MUSE observations reveal an extended gas tail stretching over 30 kpc from the galaxy, tracing ongoing ram pressure stripping as it falls into the Norma galaxy cluster.
2) Analysis of the gas kinematics and stellar velocity field show that ram pressure has removed the interstellar medium from the outer disk while the primary tail is still fed by gas from the galaxy center.
3) The stripped gas retains evidence of the disk's rotational velocity out to 20 kpc downstream, indicating the galaxy is moving radially through the cluster. Beyond this the gas shows greater turbulence,
Dust in the_polar_region_as_a_major_contributor_to_the_infrared_emission_of_a...Sérgio Sacani
The mid-infrared emission of the active galactic nucleus NGC 3783 was observed using interferometry over multiple epochs, providing dense coverage of position angles and baselines. The emission was found to be strongly elongated along a position angle of -52 degrees, closely aligned with the polar axis orientation of -45 degrees. The half-light radii were measured to be 20.0 mas by 6.7 mas, corresponding to an axis ratio of 3:1. This implies that 60-90% of the 8-13 micron emission is from the polar-elongated component. The observations support a scenario where the majority of mid-infrared emission in Seyfert galaxies originates from a dusty wind in the polar region,
The ASTRODEEP Frontier Fields catalogues II. Photometric redshifts and rest f...Sérgio Sacani
This document describes a public release of photometric redshifts and galaxy properties from multi-wavelength data in the Abell-2744 and MACS-J0416 galaxy cluster fields observed as part of the Frontier Fields program. Photometric redshifts were estimated using six different methods and have an accuracy of 3-5%. Accounting for gravitational lensing magnification, the H-band number counts agree with CANDELS at bright magnitudes but extend to intrinsically fainter galaxies of H=32-33. The Frontier Fields data allow probing galaxy stellar masses 0.5-1.5 dex lower than in wide fields, including sources with masses of 107-108 solar masses at z>5. Star formation rates can be detected 1
Exocometary gas in_th_hd_181327_debris_ringSérgio Sacani
An increasing number of observations have shown that gaseous debris discs are not an
exception. However, until now we only knew of cases around A stars. Here we present the first
detection of 12CO (2-1) disc emission around an F star, HD 181327, obtained with ALMA
observations at 1.3 mm. The continuum and CO emission are resolved into an axisymmetric
disc with ring-like morphology. Using a Markov chain Monte Carlo method coupled with
radiative transfer calculations we study the dust and CO mass distribution. We find the dust is
distributed in a ring with a radius of 86:0 0:4 AU and a radial width of 23:2 1:0 AU. At
this frequency the ring radius is smaller than in the optical, revealing grain size segregation
expected due to radiation pressure. We also report on the detection of low level continuum
emission beyond the main ring out to 200 AU. We model the CO emission in the non-LTE
regime and we find that the CO is co-located with the dust, with a total CO gas mass ranging
between 1:2 10 6 M and 2:9 10 6 M, depending on the gas kinetic temperature and
collisional partners densities. The CO densities and location suggest a secondary origin, i.e.
released from icy planetesimals in the ring. We derive a CO cometary composition that is
consistent with Solar system comets. Due to the low gas densities it is unlikely that the gas is
shaping the dust distribution.
A multi wavelength_analysis_of_m8_insight_on_the_nature_of_arp_loopSérgio Sacani
This document presents a multi-wavelength analysis of M81 and Arp's loop, a peculiar ring-like structure around M81. Optical images reveal Arp's loop has a filamentary structure with many overlapping dust features. Infrared images show Arp's loop has infrared colors and emission properties similar to Galactic cirrus clouds in the region. The results suggest the light at optical wavelengths comes from recent star formation near M81, M81's extended disk, and scattered light from Galactic cirrus, while the infrared emission is dominated by cold dust from Galactic cirrus.
This document summarizes the results of a sub-mm survey of the Carina Nebula complex conducted with the LABOCA instrument on the APEX telescope. The survey mapped an area of 1.25° × 1.25° at 870 μm, revealing the morphology and distribution of cold dust clouds with masses down to a few solar masses. The total mass of clouds detected is estimated to be around 60,000 M☉. The cloud morphologies range from large clouds of several thousand solar masses to small diffuse clouds of only a few solar masses. The distribution of sub-mm emission generally agrees with Spitzer 8 μm maps, identifying clouds interacting with massive stars as well as infrared dark clouds. The survey provides crucial
Probing the jet_base_of_blazar_pks1830211_from_the_chromatic_variability_of_i...Sérgio Sacani
This document summarizes ALMA observations of the blazar PKS 1830-211 taken over multiple epochs in 2012. The blazar is lensed by a foreground galaxy, producing two resolved images (NE and SW) separated by 1". The observations were taken at frequencies corresponding to 350-1050 GHz in the blazar rest frame. Analysis of the flux ratio between the two images over time and frequency revealed a remarkable frequency-dependent behavior, implying a "chromatic structure" in the blazar jet. This is interpreted as evidence for a "core-shift effect" caused by plasmon ejection very near the base of the jet. The observations provide a unique probe of activity in the region where plasma acceleration occurs in blazar
X-rays from a Central “Exhaust Vent” of the Galactic Center ChimneySérgio Sacani
Using deep archival observations from the Chandra X-ray Observatory, we present an analysis of
linear X-ray-emitting features located within the southern portion of the Galactic center chimney,
and oriented orthogonal to the Galactic plane, centered at coordinates l = 0.08◦
, b = −1.42◦
. The
surface brightness and hardness ratio patterns are suggestive of a cylindrical morphology which may
have been produced by a plasma outflow channel extending from the Galactic center. Our fits of the
feature’s spectra favor a complex two-component model consisting of thermal and recombining plasma
components, possibly a sign of shock compression or heating of the interstellar medium by outflowing
material. Assuming a recombining plasma scenario, we further estimate the cooling timescale of this
plasma to be on the order of a few hundred to thousands of years, leading us to speculate that a
sequence of accretion events onto the Galactic Black Hole may be a plausible quasi-continuous energy
source to sustain the observed morphology
Fleeting Small-scale Surface Magnetic Fields Build the Quiet-Sun CoronaSérgio Sacani
Arch-like loop structures filled with million Kelvin hot plasma form the building blocks of the quiet-Sun corona.
Both high-resolution observations and magnetoconvection simulations show the ubiquitous presence of magnetic
fields on the solar surface on small spatial scales of ∼100 km. However, the question of how exactly these quietSun coronal loops originate from the photosphere and how the magnetic energy from the surface is channeled to
heat the overlying atmosphere is a long-standing puzzle. Here we report high-resolution photospheric magnetic
field and coronal data acquired during the second science perihelion of Solar Orbiter that reveal a highly dynamic
magnetic landscape underlying the observed quiet-Sun corona. We found that coronal loops often connect to
surface regions that harbor fleeting weaker, mixed-polarity magnetic field patches structured on small spatial
scales, and that coronal disturbances could emerge from these areas. We suggest that weaker magnetic fields with
fluxes as low as 1015 Mx and/or those that evolve on timescales less than 5 minutes are crucial to understanding
the coronal structuring and dynamics.
This document summarizes a survey of the massive star forming region RCW 57 (NGC 3576) using JHKs and L-band (3.5 μm) infrared data. Over 50% of the sources detected showed infrared excess emission, indicating the presence of circumstellar disks. Comparison to other regions supported a very high initial disk fraction (>80%) around massive stars, though disks may dissipate faster around high-mass stars. 33 sources only detected at L-band indicated heavily embedded, massive Class I protostars. Diffuse polycyclic aromatic hydrocarbon emission was also detected throughout the region.
AT2023fhn (the Finch): a Luminous Fast Blue Optical Transient at a large offs...Sérgio Sacani
Luminous Fast Blue Optical Transients (LFBOTs) - the prototypical example being AT 2018cow - are a rare class of events
whose origins are poorly understood. They are characterised by rapid evolution, featureless blue spectra at early times, and
luminous X-ray and radio emission. LFBOTs thus far have been found exclusively at small projected offsets from star-forming
host galaxies. We present Hubble Space Telescope, Gemini, Chandra and Very Large Array observations of a new LFBOT,
AT 2023fhn. The Hubble Space Telescope data reveal a large offset (> 3.5 half-light radii) from the two closest galaxies, both
at redshift 𝑧 ∼ 0.24. The location of AT 2023fhn is in stark contrast with previous events, and demonstrates that LFBOTs can
occur in a range of galactic environments.
Radio continum emission_of_35_edge_on_galaxies_observed_with_the_vlaSérgio Sacani
Usando um dos maiores rádio observatórios do mundo, o Very Large Array do National Radio Astronomy, um grupo de astrônomos descobriram que os halos ao redor dos discos das galáxias espirais são muito mais comuns do que se pensava anteriormente.
A equipe, dirigida pela Dra. Judith Irwin, da Universidade de Queens, em Kingston, ON, Canadá, observou 35 galáxias espirais próximas de lado, de 11 a 137 milhões de anos-luz de distância da Terra.
As galáxias espirais, como a nossa própria Via Láctea ou a famosa Galáxia de Andrômeda, possuem uma vasta maioria de suas estrelas, gás, e poeira num disco plano em rotação com braços espirais. A maior parte da luz e das ondas de rádio observadas com telescópios veem de objetos localizados nesse disco.
“Nós sabíamos antes que alguns halos existiam, mas, usando o poder total do VLA atualizado e o poder total de algumas técnicas de processamento de imagens, nós descobrimos que esses halos são muito mais comuns entre as galáxias espirais do que nós pensávamos antes”, explicou a Dra. Irwin.
This document summarizes an infrared survey of the massive star forming region RCW 57 (NGC 3576) using L-band (3.5 μm) data from SPIREX and JHKs data from 2MASS. Over 50% of the 209 sources detected showed infrared excess, indicating circumstellar disks. Comparison to other surveys supports a very high initial disk fraction (>80%) around massive stars, though disks may dissipate faster around high-mass stars. 33 sources only detected at L-band indicate heavily embedded, massive Class I protostars. Diffuse PAH emission was also detected throughout RCW 57.
The wonderful complexity_of_the_mira_ab_systemSérgio Sacani
The ALMA observations of the Mira AB binary system reveal an amazingly complex circumstellar environment shaped by multiple dynamical processes. In the blue wing of the CO emission line, opposing large arcs form a bubble structure around Mira A, possibly created by the wind from Mira B blowing into Mira A's expanding envelope. In the main line component, spiral arcs are seen around Mira A that appear relatively flat and oriented in the orbital plane. An accretion wake is also visible trailing Mira B. The companion is marginally resolved with a separation of 0.487 arcseconds from Mira A.
Reionization and the ISM/Stellar Origins with JWST and ALMA (RIOJA): The Core...Sérgio Sacani
The protoclusters in the epoch of reionization, traced by galaxy overdensity regions, are ideal laboratories for
studying the process of stellar assembly and cosmic reionization. We present the spectroscopic confirmation of the
core of the most distant protocluster at z = 7.88, A2744-z7p9OD, with the James Webb Space Telescope NIRSpec
integral field unit spectroscopy. The core region includes as many as four galaxies detected in [O III] 4960 and
5008 Å in a small area of ∼3″ × 3″, corresponding to ∼11 × 11 kpc, after the lensing magnification correction.
Three member galaxies are also tentatively detected in dust continuum in Atacama Large Millimeter/submillimeter
Array Band 6, which is consistent with their red ultraviolet continuum slopes, β ∼ −1.3. The member galaxies
have stellar masses in the range of log(M*/Me) ∼7.6–9.2 and star formation rates of ∼3–50 Me yr−1
, showing a
diversity in their properties. FirstLight cosmological simulations reproduce the physical properties of the member
galaxies including the stellar mass, [O III] luminosity, and dust-to-stellar mass ratio, and predict that the member
galaxies are on the verge of merging in a few to several tens of Myr to become a large galaxy with
M* ∼ 6 × 109
Me. The presence of a multiple merger and evolved galaxies in the core region of A2744-z7p9OD
indicates that environmental effects are already at work 650 Myr after the Big Bang.
Todo mundo sabe que os raios produzidos pela Estrela da Morte em Guerra nas Estrelas não pode existir na vida real, porém no universo existem fenômenos que as vezes conseguem superar até a mais surpreendente ficção.
A galáxia Pictor A, é um desses objetos que possuem fenômenos tão espetaculares quanto aqueles exibidos no cinema. Essa galáxia localiza-se a cerca de 500 milhões de anos-luz da Terra e possui um buraco negro supermassivo no seu centro. Uma grande quantidade de energia gravitacional é lançada, à medida que o material cai em direção ao horizonte de eventos, o ponto sem volta ao redor do buraco negro. Essa energia produz um enorme jato de partículas que viajam a uma velocidade próxima da velocidade da luz no espaço intergaláctico, chamado de jato relativístico.
Para obter imagens desse jato, os cientistas usaram o Observatório de Raios-X Chandra, da NASA várias vezes durante 15 anos. Os dados do Chandra, apresentados em azul nas imagens, foram combinados com os dados obtidos em ondas de rádio a partir do Australia Telescope Compact Array, e são aparesentados em vermelho nas imagens.
An ultrahot gas-giant exoplanet with a stratosphereSérgio Sacani
Infrared radiation emitted from a planet contains information
about the chemical composition and vertical temperature profile
of its atmosphere1–3. If upper layers are cooler than lower layers,
molecular gases will produce absorption features in the planetary
thermal spectrum4,5
. Conversely, if there is a stratosphere—
where temperature increases with altitude—these molecular
features will be observed in emission6–8. It has been suggested that
stratospheres could form in highly irradiated exoplanets9,10, but
the extent to which this occurs is unresolved both theoretically11,12
and observationally3,13–15. A previous claim for the presence of a
stratosphere14 remains open to question, owing to the challenges
posed by the highly variable host star and the low spectral resolution
of the measurements3
. Here we report a near-infrared thermal
spectrum for the ultrahot gas giant WASP-121b, which has an
equilibrium temperature of approximately 2,500 kelvin. Water
is resolved in emission, providing a detection of an exoplanet
stratosphere at 5σ confidence. These observations imply that a
substantial fraction of incident stellar radiation is retained at high
altitudes in the atmosphere, possibly by absorbing chemical species
such as gaseous vanadium oxide and titanium oxide
Dust production and_particle_acceleration_in_supernova_1987_a_revealed_with_almaSérgio Sacani
This document presents spatially resolved submillimeter observations of supernova remnant SN 1987A using the Atacama Large Millimeter/Submillimeter Array (ALMA). The observations reveal that at longer wavelengths (2.8 mm - 1.4 mm), the emission is from a torus associated with the supernova shock wave, while at shorter wavelengths (870 μm - 450 μm) the emission is dominated by the inner supernova ejecta. For the first time, the dust emission is unambiguously shown to originate from the inner ejecta rather than from the surrounding material, supporting theoretical models of significant dust production in supernovae. The observations also allow separation of synchrotron emission from shock-accelerated particles in
Imaging the Milky Way with Millihertz Gravitational WavesSérgio Sacani
Modern astronomers enjoy access to all-sky images across a wide range of the electromagnetic spectrum from
long-wavelength radio to high-energy gamma rays. The most prominent feature in many of these images is our
own Galaxy, with different features revealed in each wave band. Gravitational waves (GWs) have recently been
added to the astronomers’ toolkit as a nonelectromagnetic messenger. To date, all identified GW sources have been
extra-Galactic and transient. However, the Milky Way hosts a population of ultracompact binaries (UCBs), which
radiate persistent GWs in the milliHertz band that is not observable with today’s terrestrial gravitational-wave
detectors. Space-based detectors such as the Laser Interferometer Space Antenna will measure this population and
provide a census of their location, masses, and orbital properties. In this work, we will show how this data can be
used to form a false-color image of the Galaxy that represents the intensity and frequency of the gravitational
waves produced by the UCB population. Such images can be used to study the morphology of the Galaxy, identify
interesting multimessenger sources through cross-matching, and for educational and outreach purposes.
The document summarizes Spitzer observations of the supernova remnant IC 443. The MIPS images show the remnant's morphology in great detail, resembling a shell or loop. The dust temperature ranges from 18-30 K based on the 70/160um ratio. IRS spectroscopy confirms shock-excited atomic and molecular emission, with shock velocities of 60-90 km/s. H2 excitation diagrams show temperatures of 300-600 K and column densities varying across the remnant.
Spirals and clumps in V960 Mon: signs of planet formation via gravitational i...Sérgio Sacani
The formation of giant planets has traditionally been divided into two pathways: core accretion and gravitational instability. However, in recent years, gravitational instability has become less favored, primarily due
to the scarcity of observations of fragmented protoplanetary disks around young stars and low occurrence rate
of massive planets on very wide orbits. In this study, we present a SPHERE/IRDIS polarized light observation
of the young outbursting object V960 Mon. The image reveals a vast structure of intricately shaped scattered
light with several spiral arms. This finding motivated a re-analysis of archival ALMA 1.3 mm data acquired
just two years after the onset of the outburst of V960 Mon. In these data, we discover several clumps of continuum emission aligned along a spiral arm that coincides with the scattered light structure. We interpret the
localized emission as fragments formed from a spiral arm under gravitational collapse. Estimating the mass of
solids within these clumps to be of several Earth masses, we suggest this observation to be the first evidence of
gravitational instability occurring on planetary scales. This study discusses the significance of this finding for
planet formation and its potential connection with the outbursting state of V960 Mon.
M82 X-2 is the first pulsating ultraluminous X-ray source discovered. The luminosity of these extreme pulsars, if
isotropic, implies an extreme mass transfer rate. An alternative is to assume a much lower mass transfer rate, but
with an apparent luminosity boosted by geometrical beaming. Only an independent measurement of the mass
transfer rate can help discriminate between these two scenarios. In this paper, we follow the orbit of the neutron star
for 7 yr, measure the decay of the orbit (P P orb orb 8 10 yr 6 1 · » - - - ), and argue that this orbital decay is driven by
extreme mass transfer of more than 150 times the mass transfer limit set by the Eddington luminosity. If this is true,
the mass available to the accretor is more than enough to justify its luminosity, with no need for beaming. This also
strongly favors models where the accretor is a highly magnetized neutron star.
A dust obscured_massive_maximum_starburst_galaxy_at_a_redshift_634Sérgio Sacani
This document summarizes the discovery of a massive, intensely star-forming galaxy located at a redshift of 6.34, approximately 880 million years after the Big Bang. Observations revealed a suite of molecular and atomic emission and absorption lines that unambiguously determined the galaxy's redshift. Analysis shows the galaxy contains over 100 billion solar masses of chemically evolved interstellar medium, constituting at least 40% of its baryonic mass. It is forming new stars at a rate over 2,000 times that of the Milky Way, making it a "maximum starburst" galaxy. Despite an overall decline in cosmic star formation at the highest redshifts, this discovery shows that environments capable of hosting the most massive starbursts existed very early
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Mais conteúdo relacionado
Semelhante a ALMA Observations of the Extraordinary Carina Pillars: A Complementary Sample
A multi wavelength_analysis_of_m8_insight_on_the_nature_of_arp_loopSérgio Sacani
This document presents a multi-wavelength analysis of M81 and Arp's loop, a peculiar ring-like structure around M81. Optical images reveal Arp's loop has a filamentary structure with many overlapping dust features. Infrared images show Arp's loop has infrared colors and emission properties similar to Galactic cirrus clouds in the region. The results suggest the light at optical wavelengths comes from recent star formation near M81, M81's extended disk, and scattered light from Galactic cirrus, while the infrared emission is dominated by cold dust from Galactic cirrus.
This document summarizes the results of a sub-mm survey of the Carina Nebula complex conducted with the LABOCA instrument on the APEX telescope. The survey mapped an area of 1.25° × 1.25° at 870 μm, revealing the morphology and distribution of cold dust clouds with masses down to a few solar masses. The total mass of clouds detected is estimated to be around 60,000 M☉. The cloud morphologies range from large clouds of several thousand solar masses to small diffuse clouds of only a few solar masses. The distribution of sub-mm emission generally agrees with Spitzer 8 μm maps, identifying clouds interacting with massive stars as well as infrared dark clouds. The survey provides crucial
Probing the jet_base_of_blazar_pks1830211_from_the_chromatic_variability_of_i...Sérgio Sacani
This document summarizes ALMA observations of the blazar PKS 1830-211 taken over multiple epochs in 2012. The blazar is lensed by a foreground galaxy, producing two resolved images (NE and SW) separated by 1". The observations were taken at frequencies corresponding to 350-1050 GHz in the blazar rest frame. Analysis of the flux ratio between the two images over time and frequency revealed a remarkable frequency-dependent behavior, implying a "chromatic structure" in the blazar jet. This is interpreted as evidence for a "core-shift effect" caused by plasmon ejection very near the base of the jet. The observations provide a unique probe of activity in the region where plasma acceleration occurs in blazar
X-rays from a Central “Exhaust Vent” of the Galactic Center ChimneySérgio Sacani
Using deep archival observations from the Chandra X-ray Observatory, we present an analysis of
linear X-ray-emitting features located within the southern portion of the Galactic center chimney,
and oriented orthogonal to the Galactic plane, centered at coordinates l = 0.08◦
, b = −1.42◦
. The
surface brightness and hardness ratio patterns are suggestive of a cylindrical morphology which may
have been produced by a plasma outflow channel extending from the Galactic center. Our fits of the
feature’s spectra favor a complex two-component model consisting of thermal and recombining plasma
components, possibly a sign of shock compression or heating of the interstellar medium by outflowing
material. Assuming a recombining plasma scenario, we further estimate the cooling timescale of this
plasma to be on the order of a few hundred to thousands of years, leading us to speculate that a
sequence of accretion events onto the Galactic Black Hole may be a plausible quasi-continuous energy
source to sustain the observed morphology
Fleeting Small-scale Surface Magnetic Fields Build the Quiet-Sun CoronaSérgio Sacani
Arch-like loop structures filled with million Kelvin hot plasma form the building blocks of the quiet-Sun corona.
Both high-resolution observations and magnetoconvection simulations show the ubiquitous presence of magnetic
fields on the solar surface on small spatial scales of ∼100 km. However, the question of how exactly these quietSun coronal loops originate from the photosphere and how the magnetic energy from the surface is channeled to
heat the overlying atmosphere is a long-standing puzzle. Here we report high-resolution photospheric magnetic
field and coronal data acquired during the second science perihelion of Solar Orbiter that reveal a highly dynamic
magnetic landscape underlying the observed quiet-Sun corona. We found that coronal loops often connect to
surface regions that harbor fleeting weaker, mixed-polarity magnetic field patches structured on small spatial
scales, and that coronal disturbances could emerge from these areas. We suggest that weaker magnetic fields with
fluxes as low as 1015 Mx and/or those that evolve on timescales less than 5 minutes are crucial to understanding
the coronal structuring and dynamics.
This document summarizes a survey of the massive star forming region RCW 57 (NGC 3576) using JHKs and L-band (3.5 μm) infrared data. Over 50% of the sources detected showed infrared excess emission, indicating the presence of circumstellar disks. Comparison to other regions supported a very high initial disk fraction (>80%) around massive stars, though disks may dissipate faster around high-mass stars. 33 sources only detected at L-band indicated heavily embedded, massive Class I protostars. Diffuse polycyclic aromatic hydrocarbon emission was also detected throughout the region.
AT2023fhn (the Finch): a Luminous Fast Blue Optical Transient at a large offs...Sérgio Sacani
Luminous Fast Blue Optical Transients (LFBOTs) - the prototypical example being AT 2018cow - are a rare class of events
whose origins are poorly understood. They are characterised by rapid evolution, featureless blue spectra at early times, and
luminous X-ray and radio emission. LFBOTs thus far have been found exclusively at small projected offsets from star-forming
host galaxies. We present Hubble Space Telescope, Gemini, Chandra and Very Large Array observations of a new LFBOT,
AT 2023fhn. The Hubble Space Telescope data reveal a large offset (> 3.5 half-light radii) from the two closest galaxies, both
at redshift 𝑧 ∼ 0.24. The location of AT 2023fhn is in stark contrast with previous events, and demonstrates that LFBOTs can
occur in a range of galactic environments.
Radio continum emission_of_35_edge_on_galaxies_observed_with_the_vlaSérgio Sacani
Usando um dos maiores rádio observatórios do mundo, o Very Large Array do National Radio Astronomy, um grupo de astrônomos descobriram que os halos ao redor dos discos das galáxias espirais são muito mais comuns do que se pensava anteriormente.
A equipe, dirigida pela Dra. Judith Irwin, da Universidade de Queens, em Kingston, ON, Canadá, observou 35 galáxias espirais próximas de lado, de 11 a 137 milhões de anos-luz de distância da Terra.
As galáxias espirais, como a nossa própria Via Láctea ou a famosa Galáxia de Andrômeda, possuem uma vasta maioria de suas estrelas, gás, e poeira num disco plano em rotação com braços espirais. A maior parte da luz e das ondas de rádio observadas com telescópios veem de objetos localizados nesse disco.
“Nós sabíamos antes que alguns halos existiam, mas, usando o poder total do VLA atualizado e o poder total de algumas técnicas de processamento de imagens, nós descobrimos que esses halos são muito mais comuns entre as galáxias espirais do que nós pensávamos antes”, explicou a Dra. Irwin.
This document summarizes an infrared survey of the massive star forming region RCW 57 (NGC 3576) using L-band (3.5 μm) data from SPIREX and JHKs data from 2MASS. Over 50% of the 209 sources detected showed infrared excess, indicating circumstellar disks. Comparison to other surveys supports a very high initial disk fraction (>80%) around massive stars, though disks may dissipate faster around high-mass stars. 33 sources only detected at L-band indicate heavily embedded, massive Class I protostars. Diffuse PAH emission was also detected throughout RCW 57.
The wonderful complexity_of_the_mira_ab_systemSérgio Sacani
The ALMA observations of the Mira AB binary system reveal an amazingly complex circumstellar environment shaped by multiple dynamical processes. In the blue wing of the CO emission line, opposing large arcs form a bubble structure around Mira A, possibly created by the wind from Mira B blowing into Mira A's expanding envelope. In the main line component, spiral arcs are seen around Mira A that appear relatively flat and oriented in the orbital plane. An accretion wake is also visible trailing Mira B. The companion is marginally resolved with a separation of 0.487 arcseconds from Mira A.
Reionization and the ISM/Stellar Origins with JWST and ALMA (RIOJA): The Core...Sérgio Sacani
The protoclusters in the epoch of reionization, traced by galaxy overdensity regions, are ideal laboratories for
studying the process of stellar assembly and cosmic reionization. We present the spectroscopic confirmation of the
core of the most distant protocluster at z = 7.88, A2744-z7p9OD, with the James Webb Space Telescope NIRSpec
integral field unit spectroscopy. The core region includes as many as four galaxies detected in [O III] 4960 and
5008 Å in a small area of ∼3″ × 3″, corresponding to ∼11 × 11 kpc, after the lensing magnification correction.
Three member galaxies are also tentatively detected in dust continuum in Atacama Large Millimeter/submillimeter
Array Band 6, which is consistent with their red ultraviolet continuum slopes, β ∼ −1.3. The member galaxies
have stellar masses in the range of log(M*/Me) ∼7.6–9.2 and star formation rates of ∼3–50 Me yr−1
, showing a
diversity in their properties. FirstLight cosmological simulations reproduce the physical properties of the member
galaxies including the stellar mass, [O III] luminosity, and dust-to-stellar mass ratio, and predict that the member
galaxies are on the verge of merging in a few to several tens of Myr to become a large galaxy with
M* ∼ 6 × 109
Me. The presence of a multiple merger and evolved galaxies in the core region of A2744-z7p9OD
indicates that environmental effects are already at work 650 Myr after the Big Bang.
Todo mundo sabe que os raios produzidos pela Estrela da Morte em Guerra nas Estrelas não pode existir na vida real, porém no universo existem fenômenos que as vezes conseguem superar até a mais surpreendente ficção.
A galáxia Pictor A, é um desses objetos que possuem fenômenos tão espetaculares quanto aqueles exibidos no cinema. Essa galáxia localiza-se a cerca de 500 milhões de anos-luz da Terra e possui um buraco negro supermassivo no seu centro. Uma grande quantidade de energia gravitacional é lançada, à medida que o material cai em direção ao horizonte de eventos, o ponto sem volta ao redor do buraco negro. Essa energia produz um enorme jato de partículas que viajam a uma velocidade próxima da velocidade da luz no espaço intergaláctico, chamado de jato relativístico.
Para obter imagens desse jato, os cientistas usaram o Observatório de Raios-X Chandra, da NASA várias vezes durante 15 anos. Os dados do Chandra, apresentados em azul nas imagens, foram combinados com os dados obtidos em ondas de rádio a partir do Australia Telescope Compact Array, e são aparesentados em vermelho nas imagens.
An ultrahot gas-giant exoplanet with a stratosphereSérgio Sacani
Infrared radiation emitted from a planet contains information
about the chemical composition and vertical temperature profile
of its atmosphere1–3. If upper layers are cooler than lower layers,
molecular gases will produce absorption features in the planetary
thermal spectrum4,5
. Conversely, if there is a stratosphere—
where temperature increases with altitude—these molecular
features will be observed in emission6–8. It has been suggested that
stratospheres could form in highly irradiated exoplanets9,10, but
the extent to which this occurs is unresolved both theoretically11,12
and observationally3,13–15. A previous claim for the presence of a
stratosphere14 remains open to question, owing to the challenges
posed by the highly variable host star and the low spectral resolution
of the measurements3
. Here we report a near-infrared thermal
spectrum for the ultrahot gas giant WASP-121b, which has an
equilibrium temperature of approximately 2,500 kelvin. Water
is resolved in emission, providing a detection of an exoplanet
stratosphere at 5σ confidence. These observations imply that a
substantial fraction of incident stellar radiation is retained at high
altitudes in the atmosphere, possibly by absorbing chemical species
such as gaseous vanadium oxide and titanium oxide
Dust production and_particle_acceleration_in_supernova_1987_a_revealed_with_almaSérgio Sacani
This document presents spatially resolved submillimeter observations of supernova remnant SN 1987A using the Atacama Large Millimeter/Submillimeter Array (ALMA). The observations reveal that at longer wavelengths (2.8 mm - 1.4 mm), the emission is from a torus associated with the supernova shock wave, while at shorter wavelengths (870 μm - 450 μm) the emission is dominated by the inner supernova ejecta. For the first time, the dust emission is unambiguously shown to originate from the inner ejecta rather than from the surrounding material, supporting theoretical models of significant dust production in supernovae. The observations also allow separation of synchrotron emission from shock-accelerated particles in
Imaging the Milky Way with Millihertz Gravitational WavesSérgio Sacani
Modern astronomers enjoy access to all-sky images across a wide range of the electromagnetic spectrum from
long-wavelength radio to high-energy gamma rays. The most prominent feature in many of these images is our
own Galaxy, with different features revealed in each wave band. Gravitational waves (GWs) have recently been
added to the astronomers’ toolkit as a nonelectromagnetic messenger. To date, all identified GW sources have been
extra-Galactic and transient. However, the Milky Way hosts a population of ultracompact binaries (UCBs), which
radiate persistent GWs in the milliHertz band that is not observable with today’s terrestrial gravitational-wave
detectors. Space-based detectors such as the Laser Interferometer Space Antenna will measure this population and
provide a census of their location, masses, and orbital properties. In this work, we will show how this data can be
used to form a false-color image of the Galaxy that represents the intensity and frequency of the gravitational
waves produced by the UCB population. Such images can be used to study the morphology of the Galaxy, identify
interesting multimessenger sources through cross-matching, and for educational and outreach purposes.
The document summarizes Spitzer observations of the supernova remnant IC 443. The MIPS images show the remnant's morphology in great detail, resembling a shell or loop. The dust temperature ranges from 18-30 K based on the 70/160um ratio. IRS spectroscopy confirms shock-excited atomic and molecular emission, with shock velocities of 60-90 km/s. H2 excitation diagrams show temperatures of 300-600 K and column densities varying across the remnant.
Spirals and clumps in V960 Mon: signs of planet formation via gravitational i...Sérgio Sacani
The formation of giant planets has traditionally been divided into two pathways: core accretion and gravitational instability. However, in recent years, gravitational instability has become less favored, primarily due
to the scarcity of observations of fragmented protoplanetary disks around young stars and low occurrence rate
of massive planets on very wide orbits. In this study, we present a SPHERE/IRDIS polarized light observation
of the young outbursting object V960 Mon. The image reveals a vast structure of intricately shaped scattered
light with several spiral arms. This finding motivated a re-analysis of archival ALMA 1.3 mm data acquired
just two years after the onset of the outburst of V960 Mon. In these data, we discover several clumps of continuum emission aligned along a spiral arm that coincides with the scattered light structure. We interpret the
localized emission as fragments formed from a spiral arm under gravitational collapse. Estimating the mass of
solids within these clumps to be of several Earth masses, we suggest this observation to be the first evidence of
gravitational instability occurring on planetary scales. This study discusses the significance of this finding for
planet formation and its potential connection with the outbursting state of V960 Mon.
M82 X-2 is the first pulsating ultraluminous X-ray source discovered. The luminosity of these extreme pulsars, if
isotropic, implies an extreme mass transfer rate. An alternative is to assume a much lower mass transfer rate, but
with an apparent luminosity boosted by geometrical beaming. Only an independent measurement of the mass
transfer rate can help discriminate between these two scenarios. In this paper, we follow the orbit of the neutron star
for 7 yr, measure the decay of the orbit (P P orb orb 8 10 yr 6 1 · » - - - ), and argue that this orbital decay is driven by
extreme mass transfer of more than 150 times the mass transfer limit set by the Eddington luminosity. If this is true,
the mass available to the accretor is more than enough to justify its luminosity, with no need for beaming. This also
strongly favors models where the accretor is a highly magnetized neutron star.
A dust obscured_massive_maximum_starburst_galaxy_at_a_redshift_634Sérgio Sacani
This document summarizes the discovery of a massive, intensely star-forming galaxy located at a redshift of 6.34, approximately 880 million years after the Big Bang. Observations revealed a suite of molecular and atomic emission and absorption lines that unambiguously determined the galaxy's redshift. Analysis shows the galaxy contains over 100 billion solar masses of chemically evolved interstellar medium, constituting at least 40% of its baryonic mass. It is forming new stars at a rate over 2,000 times that of the Milky Way, making it a "maximum starburst" galaxy. Despite an overall decline in cosmic star formation at the highest redshifts, this discovery shows that environments capable of hosting the most massive starbursts existed very early
Semelhante a ALMA Observations of the Extraordinary Carina Pillars: A Complementary Sample (20)
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Tr...Sérgio Sacani
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the
atmospheres of terrestrial planets via follow-up spectroscopic observations. However, the number of such planets
receiving low insolation is still small, limiting our ability to understand the diversity of the atmospheric
composition and climates of temperate terrestrial planets. We report the discovery of an Earth-sized planet
transiting the nearby (12 pc) inactive M3.0 dwarf Gliese 12 (TOI-6251) with an orbital period (Porb) of 12.76 days.
The planet, Gliese 12 b, was initially identified as a candidate with an ambiguous Porb from TESS data. We
confirmed the transit signal and Porb using ground-based photometry with MuSCAT2 and MuSCAT3, and
validated the planetary nature of the signal using high-resolution images from Gemini/NIRI and Keck/NIRC2 as
well as radial velocity (RV) measurements from the InfraRed Doppler instrument on the Subaru 8.2 m telescope
and from CARMENES on the CAHA 3.5 m telescope. X-ray observations with XMM-Newton showed the host
star is inactive, with an X-ray-to-bolometric luminosity ratio of log 5.7 L L X bol » - . Joint analysis of the light
curves and RV measurements revealed that Gliese 12 b has a radius of 0.96 ± 0.05 R⊕,a3σ mass upper limit of
3.9 M⊕, and an equilibrium temperature of 315 ± 6 K assuming zero albedo. The transmission spectroscopy metric
(TSM) value of Gliese 12 b is close to the TSM values of the TRAPPIST-1 planets, adding Gliese 12 b to the small
list of potentially terrestrial, temperate planets amenable to atmospheric characterization with JWST.
Gliese 12 b, a temperate Earth-sized planet at 12 parsecs discovered with TES...Sérgio Sacani
We report on the discovery of Gliese 12 b, the nearest transiting temperate, Earth-sized planet found to date. Gliese 12 is a
bright (V = 12.6 mag, K = 7.8 mag) metal-poor M4V star only 12.162 ± 0.005 pc away from the Solar system with one of the
lowest stellar activity levels known for M-dwarfs. A planet candidate was detected by TESS based on only 3 transits in sectors
42, 43, and 57, with an ambiguity in the orbital period due to observational gaps. We performed follow-up transit observations
with CHEOPS and ground-based photometry with MINERVA-Australis, SPECULOOS, and Purple Mountain Observatory,
as well as further TESS observations in sector 70. We statistically validate Gliese 12 b as a planet with an orbital period of
12.76144 ± 0.00006 d and a radius of 1.0 ± 0.1 R⊕, resulting in an equilibrium temperature of ∼315 K. Gliese 12 b has excellent
future prospects for precise mass measurement, which may inform how planetary internal structure is affected by the stellar
compositional environment. Gliese 12 b also represents one of the best targets to study whether Earth-like planets orbiting cool
stars can retain their atmospheres, a crucial step to advance our understanding of habitability on Earth and across the galaxy.
The importance of continents, oceans and plate tectonics for the evolution of...Sérgio Sacani
Within the uncertainties of involved astronomical and biological parameters, the Drake Equation
typically predicts that there should be many exoplanets in our galaxy hosting active, communicative
civilizations (ACCs). These optimistic calculations are however not supported by evidence, which is
often referred to as the Fermi Paradox. Here, we elaborate on this long-standing enigma by showing
the importance of planetary tectonic style for biological evolution. We summarize growing evidence
that a prolonged transition from Mesoproterozoic active single lid tectonics (1.6 to 1.0 Ga) to modern
plate tectonics occurred in the Neoproterozoic Era (1.0 to 0.541 Ga), which dramatically accelerated
emergence and evolution of complex species. We further suggest that both continents and oceans
are required for ACCs because early evolution of simple life must happen in water but late evolution
of advanced life capable of creating technology must happen on land. We resolve the Fermi Paradox
(1) by adding two additional terms to the Drake Equation: foc
(the fraction of habitable exoplanets
with significant continents and oceans) and fpt
(the fraction of habitable exoplanets with significant
continents and oceans that have had plate tectonics operating for at least 0.5 Ga); and (2) by
demonstrating that the product of foc
and fpt
is very small (< 0.00003–0.002). We propose that the lack
of evidence for ACCs reflects the scarcity of long-lived plate tectonics and/or continents and oceans on
exoplanets with primitive life.
A Giant Impact Origin for the First Subduction on EarthSérgio Sacani
Hadean zircons provide a potential record of Earth's earliest subduction 4.3 billion years ago. Itremains enigmatic how subduction could be initiated so soon after the presumably Moon‐forming giant impact(MGI). Earlier studies found an increase in Earth's core‐mantle boundary (CMB) temperature due to theaccumulation of the impactor's core, and our recent work shows Earth's lower mantle remains largely solid, withsome of the impactor's mantle potentially surviving as the large low‐shear velocity provinces (LLSVPs). Here,we show that a hot post‐impact CMB drives the initiation of strong mantle plumes that can induce subductioninitiation ∼200 Myr after the MGI. 2D and 3D thermomechanical computations show that a high CMBtemperature is the primary factor triggering early subduction, with enrichment of heat‐producing elements inLLSVPs as another potential factor. The models link the earliest subduction to the MGI with implications forunderstanding the diverse tectonic regimes of rocky planets.
Climate extremes likely to drive land mammal extinction during next supercont...Sérgio Sacani
Mammals have dominated Earth for approximately 55 Myr thanks to their
adaptations and resilience to warming and cooling during the Cenozoic. All
life will eventually perish in a runaway greenhouse once absorbed solar
radiation exceeds the emission of thermal radiation in several billions of
years. However, conditions rendering the Earth naturally inhospitable to
mammals may develop sooner because of long-term processes linked to
plate tectonics (short-term perturbations are not considered here). In
~250 Myr, all continents will converge to form Earth’s next supercontinent,
Pangea Ultima. A natural consequence of the creation and decay of Pangea
Ultima will be extremes in pCO2 due to changes in volcanic rifting and
outgassing. Here we show that increased pCO2, solar energy (F⨀;
approximately +2.5% W m−2 greater than today) and continentality (larger
range in temperatures away from the ocean) lead to increasing warming
hostile to mammalian life. We assess their impact on mammalian
physiological limits (dry bulb, wet bulb and Humidex heat stress indicators)
as well as a planetary habitability index. Given mammals’ continued survival,
predicted background pCO2 levels of 410–816 ppm combined with increased
F⨀ will probably lead to a climate tipping point and their mass extinction.
The results also highlight how global landmass configuration, pCO2 and F⨀
play a critical role in planetary habitability.
Constraints on Neutrino Natal Kicks from Black-Hole Binary VFTS 243Sérgio Sacani
The recently reported observation of VFTS 243 is the first example of a massive black-hole binary
system with negligible binary interaction following black-hole formation. The black-hole mass (≈10M⊙)
and near-circular orbit (e ≈ 0.02) of VFTS 243 suggest that the progenitor star experienced complete
collapse, with energy-momentum being lost predominantly through neutrinos. VFTS 243 enables us to
constrain the natal kick and neutrino-emission asymmetry during black-hole formation. At 68% confidence
level, the natal kick velocity (mass decrement) is ≲10 km=s (≲1.0M⊙), with a full probability distribution
that peaks when ≈0.3M⊙ were ejected, presumably in neutrinos, and the black hole experienced a natal
kick of 4 km=s. The neutrino-emission asymmetry is ≲4%, with best fit values of ∼0–0.2%. Such a small
neutrino natal kick accompanying black-hole formation is in agreement with theoretical predictions.
Detectability of Solar Panels as a TechnosignatureSérgio Sacani
In this work, we assess the potential detectability of solar panels made of silicon on an Earth-like
exoplanet as a potential technosignature. Silicon-based photovoltaic cells have high reflectance in the
UV-VIS and in the near-IR, within the wavelength range of a space-based flagship mission concept
like the Habitable Worlds Observatory (HWO). Assuming that only solar energy is used to provide
the 2022 human energy needs with a land cover of ∼ 2.4%, and projecting the future energy demand
assuming various growth-rate scenarios, we assess the detectability with an 8 m HWO-like telescope.
Assuming the most favorable viewing orientation, and focusing on the strong absorption edge in the
ultraviolet-to-visible (0.34 − 0.52 µm), we find that several 100s of hours of observation time is needed
to reach a SNR of 5 for an Earth-like planet around a Sun-like star at 10pc, even with a solar panel
coverage of ∼ 23% land coverage of a future Earth. We discuss the necessity of concepts like Kardeshev
Type I/II civilizations and Dyson spheres, which would aim to harness vast amounts of energy. Even
with much larger populations than today, the total energy use of human civilization would be orders of
magnitude below the threshold for causing direct thermal heating or reaching the scale of a Kardashev
Type I civilization. Any extraterrrestrial civilization that likewise achieves sustainable population
levels may also find a limit on its need to expand, which suggests that a galaxy-spanning civilization
as imagined in the Fermi paradox may not exist.
Jet reorientation in central galaxies of clusters and groups: insights from V...Sérgio Sacani
Recent observations of galaxy clusters and groups with misalignments between their central AGN jets
and X-ray cavities, or with multiple misaligned cavities, have raised concerns about the jet – bubble
connection in cooling cores, and the processes responsible for jet realignment. To investigate the
frequency and causes of such misalignments, we construct a sample of 16 cool core galaxy clusters and
groups. Using VLBA radio data we measure the parsec-scale position angle of the jets, and compare
it with the position angle of the X-ray cavities detected in Chandra data. Using the overall sample
and selected subsets, we consistently find that there is a 30% – 38% chance to find a misalignment
larger than ∆Ψ = 45◦ when observing a cluster/group with a detected jet and at least one cavity. We
determine that projection may account for an apparently large ∆Ψ only in a fraction of objects (∼35%),
and given that gas dynamical disturbances (as sloshing) are found in both aligned and misaligned
systems, we exclude environmental perturbation as the main driver of cavity – jet misalignment.
Moreover, we find that large misalignments (up to ∼ 90◦
) are favored over smaller ones (45◦ ≤ ∆Ψ ≤
70◦
), and that the change in jet direction can occur on timescales between one and a few tens of Myr.
We conclude that misalignments are more likely related to actual reorientation of the jet axis, and we
discuss several engine-based mechanisms that may cause these dramatic changes.
The solar dynamo begins near the surfaceSérgio Sacani
The magnetic dynamo cycle of the Sun features a distinct pattern: a propagating
region of sunspot emergence appears around 30° latitude and vanishes near the
equator every 11 years (ref. 1). Moreover, longitudinal flows called torsional oscillations
closely shadow sunspot migration, undoubtedly sharing a common cause2. Contrary
to theories suggesting deep origins of these phenomena, helioseismology pinpoints
low-latitude torsional oscillations to the outer 5–10% of the Sun, the near-surface
shear layer3,4. Within this zone, inwardly increasing differential rotation coupled with
a poloidal magnetic field strongly implicates the magneto-rotational instability5,6,
prominent in accretion-disk theory and observed in laboratory experiments7.
Together, these two facts prompt the general question: whether the solar dynamo is
possibly a near-surface instability. Here we report strong affirmative evidence in stark
contrast to traditional models8 focusing on the deeper tachocline. Simple analytic
estimates show that the near-surface magneto-rotational instability better explains
the spatiotemporal scales of the torsional oscillations and inferred subsurface
magnetic field amplitudes9. State-of-the-art numerical simulations corroborate these
estimates and reproduce hemispherical magnetic current helicity laws10. The dynamo
resulting from a well-understood near-surface phenomenon improves prospects
for accurate predictions of full magnetic cycles and space weather, affecting the
electromagnetic infrastructure of Earth.
Extensive Pollution of Uranus and Neptune’s Atmospheres by Upsweep of Icy Mat...Sérgio Sacani
In the Nice model of solar system formation, Uranus and Neptune undergo an orbital upheaval,
sweeping through a planetesimal disk. The region of the disk from which material is accreted by
the ice giants during this phase of their evolution has not previously been identified. We perform
direct N-body orbital simulations of the four giant planets to determine the amount and origin of solid
accretion during this orbital upheaval. We find that the ice giants undergo an extreme bombardment
event, with collision rates as much as ∼3 per hour assuming km-sized planetesimals, increasing the
total planet mass by up to ∼0.35%. In all cases, the initially outermost ice giant experiences the
largest total enhancement. We determine that for some plausible planetesimal properties, the resulting
atmospheric enrichment could potentially produce sufficient latent heat to alter the planetary cooling
timescale according to existing models. Our findings suggest that substantial accretion during this
phase of planetary evolution may have been sufficient to impact the atmospheric composition and
thermal evolution of the ice giants, motivating future work on the fate of deposited solid material.
Exomoons & Exorings with the Habitable Worlds Observatory I: On the Detection...Sérgio Sacani
The highest priority recommendation of the Astro2020 Decadal Survey for space-based astronomy
was the construction of an observatory capable of characterizing habitable worlds. In this paper series
we explore the detectability of and interference from exomoons and exorings serendipitously observed
with the proposed Habitable Worlds Observatory (HWO) as it seeks to characterize exoplanets, starting
in this manuscript with Earth-Moon analog mutual events. Unlike transits, which only occur in systems
viewed near edge-on, shadow (i.e., solar eclipse) and lunar eclipse mutual events occur in almost every
star-planet-moon system. The cadence of these events can vary widely from ∼yearly to multiple events
per day, as was the case in our younger Earth-Moon system. Leveraging previous space-based (EPOXI)
lightcurves of a Moon transit and performance predictions from the LUVOIR-B concept, we derive
the detectability of Moon analogs with HWO. We determine that Earth-Moon analogs are detectable
with observation of ∼2-20 mutual events for systems within 10 pc, and larger moons should remain
detectable out to 20 pc. We explore the extent to which exomoon mutual events can mimic planet
features and weather. We find that HWO wavelength coverage in the near-IR, specifically in the 1.4 µm
water band where large moons can outshine their host planet, will aid in differentiating exomoon signals
from exoplanet variability. Finally, we predict that exomoons formed through collision processes akin
to our Moon are more likely to be detected in younger systems, where shorter orbital periods and
favorable geometry enhance the probability and frequency of mutual events.
Emergent ribozyme behaviors in oxychlorine brines indicate a unique niche for...Sérgio Sacani
Mars is a particularly attractive candidate among known astronomical objects
to potentially host life. Results from space exploration missions have provided
insights into Martian geochemistry that indicate oxychlorine species, particularly perchlorate, are ubiquitous features of the Martian geochemical landscape. Perchlorate presents potential obstacles for known forms of life due to
its toxicity. However, it can also provide potential benefits, such as producing
brines by deliquescence, like those thought to exist on present-day Mars. Here
we show perchlorate brines support folding and catalysis of functional RNAs,
while inactivating representative protein enzymes. Additionally, we show
perchlorate and other oxychlorine species enable ribozyme functions,
including homeostasis-like regulatory behavior and ribozyme-catalyzed
chlorination of organic molecules. We suggest nucleic acids are uniquely wellsuited to hypersaline Martian environments. Furthermore, Martian near- or
subsurface oxychlorine brines, and brines found in potential lifeforms, could
provide a unique niche for biomolecular evolution.
Continuum emission from within the plunging region of black hole discsSérgio Sacani
The thermal continuum emission observed from accreting black holes across X-ray bands has the potential to be leveraged as a
powerful probe of the mass and spin of the central black hole. The vast majority of existing ‘continuum fitting’ models neglect
emission sourced at and within the innermost stable circular orbit (ISCO) of the black hole. Numerical simulations, however,
find non-zero emission sourced from these regions. In this work, we extend existing techniques by including the emission
sourced from within the plunging region, utilizing new analytical models that reproduce the properties of numerical accretion
simulations. We show that in general the neglected intra-ISCO emission produces a hot-and-small quasi-blackbody component,
but can also produce a weak power-law tail for more extreme parameter regions. A similar hot-and-small blackbody component
has been added in by hand in an ad hoc manner to previous analyses of X-ray binary spectra. We show that the X-ray spectrum
of MAXI J1820+070 in a soft-state outburst is extremely well described by a full Kerr black hole disc, while conventional
models that neglect intra-ISCO emission are unable to reproduce the data. We believe this represents the first robust detection of
intra-ISCO emission in the literature, and allows additional constraints to be placed on the MAXI J1820 + 070 black hole spin
which must be low a• < 0.5 to allow a detectable intra-ISCO region. Emission from within the ISCO is the dominant emission
component in the MAXI J1820 + 070 spectrum between 6 and 10 keV, highlighting the necessity of including this region. Our
continuum fitting model is made publicly available.
ANAMOLOUS SECONDARY GROWTH IN DICOT ROOTS.pptxRASHMI M G
Abnormal or anomalous secondary growth in plants. It defines secondary growth as an increase in plant girth due to vascular cambium or cork cambium. Anomalous secondary growth does not follow the normal pattern of a single vascular cambium producing xylem internally and phloem externally.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
Nucleophilic Addition of carbonyl compounds.pptxSSR02
Nucleophilic addition is the most important reaction of carbonyls. Not just aldehydes and ketones, but also carboxylic acid derivatives in general.
Carbonyls undergo addition reactions with a large range of nucleophiles.
Comparing the relative basicity of the nucleophile and the product is extremely helpful in determining how reversible the addition reaction is. Reactions with Grignards and hydrides are irreversible. Reactions with weak bases like halides and carboxylates generally don’t happen.
Electronic effects (inductive effects, electron donation) have a large impact on reactivity.
Large groups adjacent to the carbonyl will slow the rate of reaction.
Neutral nucleophiles can also add to carbonyls, although their additions are generally slower and more reversible. Acid catalysis is sometimes employed to increase the rate of addition.
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptx
ALMA Observations of the Extraordinary Carina Pillars: A Complementary Sample
1. Draft version October 18, 2023
Typeset using L
A
TEX twocolumn style in AASTeX631
ALMA Observations of the Extraordinary Carina Pillars: A Complementary Sample
Geovanni Cortes-Rangel,1
Luis A. Zapata,1
Pedro R. Rivera-Ortiz,1
Megan Reiter,2
Satoko Takahashi,3, 4
and
Josep M. Masqué5
1Instituto de Radioastronomı́a y Astrofı́sica, Universidad Nacional Autónoma de México,
P.O. Box 3-72, 58090, Morelia, Michoacán, México.
2Department of Physics and Astronomy, Rice University, 6100 Main St - MS 108, Houston, TX 77005, USA
3National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
4Department of Astronomical Science, The Graduate University for Advanced Studies (SOKENDAI), 2-21-1, Osawa, Mitaka, Tokyo
181-8588, Japan
5Departamento de Astronomı́a, Universidad de Guanajuato, Apartado Postal 144, 36000, Guanajuato, Guanajuato, México
ABSTRACT
We present a study of six dusty and gaseous pillars (containing the HH 1004 and HH 1010 objects)
and globules (that contain the HH 666, HH 900, HH 1006, and HH 1066 objects) localized in the Carina
nebula using sensitive and high angular resolution (∼0.3′′
) Atacama Large Millimeter/Sub-millimeter
Array (ALMA) observations. This is a more extensive study that the one presented in Cortes-Rangel
et al. (2020). As in this former study, we also analyzed the 1.3 mm continuum emission and C18
O(2−1),
N2D+
(3−2) and 12
CO(2−1) spectral lines. These new observations revealed the molecular outflows
emanating from the pillars, the dusty envelopes+disks that are exciting them, and the extended HH
objects far from their respective pillars. We reveal that the masses of the disks+envelopes are in a
range of 0.02 to 0.38 M⊙, and those for the molecular outflows are of the order of 10−3
M⊙, which
suggests that their exciting sources might be low- or intermediate-mass protostars as already revealed
in recent studies at infrared and submillimeter bands. In the regions associated with the objects HH
900 and HH 1004, we report multiple millimeter continuum sources, from where several molecular
outflows emanate.
Keywords: molecular data – techniques: interferometric – ISM: individual objects (HH 666, HH 900,
HH 1004, HH 1006, HH 1010 and HH 1066) – ISM: jets and outflows
1. INTRODUCTION
Carina, or NGC 3372, contains two very large and
massive star clusters known as Trumpler 14 (Tr14) and
Trumpler 16 (Tr16) that produce large amounts of ion-
izing light at UV wavelengths. These two massive clus-
ters together contain dozens of O-type stars on the
main sequence that reach bolometric luminosities sur-
passing the 107
L⊙ (Smith & Brooks 2008). All this
radiation permeates the vicinity of the nebula revealing
the well-known irradiated dusty pillars, protoplanetary
disks, and jets (Reiter & Smith 2013; Reiter et al. 2019,
2020a). Therefore, this is an ideal nebula with extreme
conditions to study the formation of new generations of
stars in such harsh environments.
Recently, Cortes-Rangel et al. (2020) presented
a study using 1.3 mm continuum and C18
O(2−1),
N2D+
(3−2), 13
CS(5−4), 12
CO(2−1) spectral lines ob-
tained from Atacama Large Millimeter/Sub-millimeter
Array (ALMA) observations of the Carina Pillars HH
901 and 902. These observations revealed the outflows
and the dusty compact disks that are exciting the ex-
tended and irradiated Herbig-Haro (HH) objects far
from the pillars, and they estimated that the pillars
would be photoevaporated in timescales between 104
and 105
yr by the massive stars mainly localized in Tr14
and Tr16. In addition, the circumstellar disks associated
with the HH objects 901/902 would be likely exposed to
the strong UV radiation soon after these scales of time,
so they will transform into proplyds, like those observed
in other star forming regions like in Orion (O’dell et al.
1993; Henney & O’Dell 1999). In an even more recent
study, Reiter et al. (2020a) also presented sensitive and
high angular resolution ALMA observations of the tad-
pole, a relatively small, and strongly irradiated globule
inside the Carina Nebula which surrounds the HH 900
object. The ALMA observations obtained in Cortes-
Rangel et al. (2020) for the HH 901/902, revealed the
arXiv:2310.10801v1
[astro-ph.GA]
16
Oct
2023
2. 2
disk and outflow system inside of the pillars. For this
object, Reiter et al. (2020a) reported a timescale for the
photoevaporation of ∼ 4 × 106
yr, an order of magni-
tude larger than the dynamical age determined for HH
902 Cortes-Rangel et al. (2020), a pillar closer to the
Trumpler clusters.
Both ALMA studies are an important success in re-
vealing the disk-outflow systems that are tremendously
embedded in gas+dust contained in the globule HH 900
and pillars HH 901 and 902 that cannot be studied at
optical or infrared wavelengths. Therefore, we present
a complementary study using the ALMA that includes
the pillars and globules containing the objects in the
Carina Nebula: HH 666, HH 900, HH 1004, HH 1006,
HH 1010, and HH 1066. This study allows us to reveal
the exciting sources of the HH objects, estimate with
more accuracy their physical conditions, and study how
such harsh environments affect their evolution, and, in
particular, constrain the formation of planets inside of
the circumstellar disks.
2. OBSERVATIONS AND DATA REDUCTION
The observations of the pillars and protostellar ob-
jects (HH 666, HH 900, HH 1004, HH 1006, HH 1010,
and HH 1066) were performed with the Atacama Large
Millimeter/sub-millimeter Array (ALMA) at Band 6 in
2018 January 1 and 4 (C43-6), and April 20 (C43-3) as
part of the Cycle 5 program 2017.1.00912.S. Forty three
antennas with diameters of 12 m were used for the ob-
servations, yielding baselines from 15 − 2516 m (11.5
− 1935 kλ) for C43-6 configuration and 15 − 500 m
(11.5 − 384.6 kλ) for C43-3 configuration. The primary
beam at this frequency has a full width at half-maximum
(FWHM) of about 25′′
, covering well the bulk of molec-
ular and dusty emission from the pillars.
The 1.3 mm continuum and molecular line images
were obtained from the two configurations, C43-6 and
C43-3, that had source integration times of 9 and
3.5 min, respectively. We used four spw that were
centered at the frequencies, 218.014 GHz(spw0) for
1.3 mm continuum and 219.578 GHz(spw1), 231.239
GHz(spw2), and 230.556 GHz(spw3) for line analy-
sis. The channel widths were 21.486 km s−1
for the
continuum and 333.328, 633.038 and 634.912 m s−1
for the C18
O, N2D+
and CO respectively. The to-
tal bandwidth for the continuum is about 4.3 GHz.
Three molecular lines of C18
O(2−1) (νrest= 219.56035
GHz), N2D+
(3−2) (νrest=231.31990) and 12
CO(2−1)
(νrest=230.53800 GHz) were observed in spw1, spw2 and
spw3, respectively. System temperatures were between
100 to 150 K and precipitable water vapor was between
1.3 mm and 2.2 mm. The ALMA calibration included si-
multaneous observations of the 183 GHz water line with
water vapor radiometers, used to reduce atmospheric
phase fluctuations. Quasars, J0904-5735, and J1107-
4449 were used for the band-pass and flux calibrations.
J1032-5917 was used for correcting the gain fluctuations.
The data reduction was done using the Common As-
tronomy Software Applications (CASA, CASA Team
et al. 2022) version 5.1. We concatenated the data
from both configurations (C43-6 and C43-3) with the
UVCONCAT task. Imaging of the calibrated visibilities
was done using the TCLEAN task. We used the briggs
weighting (robust = 0.5) in the TCLEAN task to obtain
the continuum and spectral lines images. We report the
parameters obtained from a two-dimensional Gaussian
fit in CASA to the continuum images at 1.3 mm, us-
ing the gaussfit tool (within the CASA viewer), which
subtracts the sky component to a selected region for
the emission distribution. We obtained the deconvolved
sizes from the synthesized beam of each image and this
Gaussian fit. The results of the physical parameters
(position, deconvolved size, flux, and rms) are shown
in Table 1. We attempted self-calibration on the con-
tinuum emission, but unfortunately, the resulting maps
did not improve significantly. Thus, we stick with the
non-self-calibrated maps.
3. RESULTS AND DISCUSSION
Our data reveal for the first time the bipolar molecu-
lar outflows emerging from HH 666/1004/1006/1010 and
1066 YSOs (Young Stellar Objects) which corresponds
very well to the optical jets previously studied by Hubble
Space Telescope (HST) using the Advanced Camera for
Surveys (ACS) (see Figures 1, 2, 4, 5, 7 and 9). In the
following subsections, we show the analysis for each sep-
arate object. We show their gas and dust structures ob-
tained with the ALMA observations together with some
estimated physical values, such as fluxes, masses, sizes,
and the comparison with their respective optical and in-
frared bulk emissions. The parameters obtained from
the observations and the reduction of the data carried
out with CASA are shown in Table 1.
3.1. HH 666
The HH 666 object, known as the axis of evil, was first
reported by Smith et al. (2004) using ground-based op-
tical and near-IR (infrared) observations that revealed
the bipolar flow emerging from the head of a dusty glob-
ule pointing in the direction of η Carinae and Tr 16.
A protostar (listed as Class I object) embedded within
the dense globule is proposed as the possible driving
source of the optical jet (detected at the center of the
3. 3
ALMA + HST
HH 666
Tr 16
Tr 14
2500 au
0.5 pc
Figure 1. A combined (optical+radio) HST and ALMA image is shown for the globule HH 666. The optical image, in green, is
the Hα emission and is showing extended optical jet, and obscured globule that houses the protostellar source. It also shows a
millimeter continuum image at 1.3 mm frequency (white contours). The upper right panel shows the zoom image. The 1.3 mm
continuum sources are denoted by white contours. The contour levels correspond to 10% to 90% of the peak flux with a step of
10%. The blue and red colors show the moment zero images obtained from CO(2−1) emission with the velocity range of -10.19
to -10.83 km s−1
for the redshifted emission, and from −11.46 to −18.45 km s−1
for the blueshifted emission. The peak of the
millimeter continuum emission is 5.87 mJy beam−1
but there is still extended emission at lower levels. The local standard rest
(LSR) system velocity of the globule is about −10 km s−1
. The white arrows indicate the directions where the star clusters Tr
14 and Tr 16 are located.
Source Position Deconvolved Size Flux RMSa
α2000 δ2000 θmaj θmin P.A. Peak Integrated Observed
[h:m:s] [◦ ′ ′′
] [milliarcsecond] [milliarcsecond] [◦
] [mJy beam−1
] [mJy] [mJy]
HH 666 10:43:51.532 -59:55:21.18 85.2 ± 4.6 68.60 ± 3.5 31 ± 12 5.87 ± 0.17 14.94 ± 0.57 0.071
HH 900 A 10:45:19.301 -59:44:22.53 576 ± 52 396 ± 42 155 ± 12 2.41 ± 0.14 8.37 ± 0.61 0.043
HH 900 B 10:45:18.797 -59:44:23.79 272 ± 52 109 ± 70 62 ± 17 0.75 ± 0.04 1.09 ± 0.09 0.043
HH 1004 A 10:46:44.989 -60:10:14.73 101 ± 9 62 ± 17.5 153 ± 13 3.51 ± 0.13 7.42 ± 0.38 0.053
HH 1004 B 10:46:44.808 -60:10:21.20 61 ± 30 44 ± 22 177 ± 71 0.62 ± 0.06 0.90 ± 0.15 0.053
HH 1004 C 10:46:44.969 -60:10:15.12 36 ± 14 17 ± 18 178 ± 49 1.32 ± 0.04 1.49 ± 0.09 0.053
HH 1006 10:46:32.902 -60:03:53.84 1139 ± 89 945 ± 75 43 ± 17 0.38 ± 0.02 9.41± 0.73 0.050
HH 1010 10:41:48.640 -59:43:38.04 point source point source − 3.96 ± 0.09 4.12 ± 0.17 0.097
HH 1066 10:44:05.395 -59:29:40.24 373 ± 85 211 ± 92 170 ± 26 1.37 ± 0.18 3.86 ± 0.66 0.053
a The theoretical rms for all sources is 0.046 mJy.
Table 1. Physical parameters of the protoplanetary disks + envelopes detected in Carina from 1.3 mm continuum images for
different sources using the reduced ALMA data.
4. 4
globule at the position in the sky of α = 10h
43m
51s
.3,
δ = −59◦
55′
21′′
.2, J2000), see Smith et al. (2004). In
a later study, Smith et al. (2010) reported new Hα ob-
servations from the HST, corroborating the jet struc-
ture associated with the HH object, the extension of
jet component (∼4′
.5 or ∼3 pc), and the detection of a
weak object located at the same position as the previous
study. This object was also detected in Spitzer near-IR
observations (Smith et al. 2010)
In recent work, Reiter et al. (2015a) presented near-IR
spectroscopic studies of [Fe II] obtained with the Folded-
Port InfraRed Echelette (FIRE) spectrograph on the
Baade/Magellan Telescope. These observations reveal
that [Fe II] emission is tracing a highly collimated pro-
tostellar jet embedded in the dense pillar of gas and dust
with an extension of about 40 arcsecs. They also found
a clear connection between the previously revealed jet
driving source and the extent of the collimated jet. Fi-
nally, their studies of [Fe II] and Hα showed differences,
especially in areas very close to the protostellar source,
where the images in Hα did not reveal any emission.
In Figure 1, we present the optical image of the
HST/ACS presented in Smith et al. (2010) overlaid with
our resulting ALMA 1.3 mm continuum and line im-
ages of the globule HH 666. The optical image (green)
corresponds to Hα emission and is overlapped with the
ALMA high velocity CO(2−1) molecular emission (blue
and red) and the 1.3 mm continuum emission (white
contours). The CO emission is tracing the bipolar out-
flow very close to the exciting source, which moves at an
LSR system velocity of −10 km s−1
. The angular size
is 1.6′′
which at 2.3 kpc represents a size of 3680 au for
HH 666.
The 1.3 mm continuum emission is only located in
the axis of the optical jet detected in Hα at α =
10h
43m
51s
.5, δ = −59◦
55′
21′′
.1 (J2000), perfectly
matching the near-IR source detected by (Smith et al.
2004) (see Figure 1) and reveals a compact source corre-
sponding to an embedded structure in the central zone
of the globule. We think that this object is composed of
a dusty envelope and circumstellar disk corresponding
to the driving source of the protostellar optical jet, and
for this millimeter continuum emission, we obtained an
integrated flux of 14.94 ± 0.57 mJy and an observed rms
noise of 0.071 mJy (see Table 1) for the continuum im-
age, which is very close to the theoretical noise value for
this configuration (43 antennas), frequency (230 GHz),
bandwidth (4.3 GHz) and integration time (12.5 min.)
and is 0.046 mJy. From a Gaussian fit in CASA for the
continuum source and the synthesized beam size (0′′
.07
× 0′′
.05), we obtained a deconvolved size of 0′′
.0852 ±
0′′
.0046 × 0′′
.0686 ± 0′′
.0035 with an PA of 31◦
± 12◦
,
Source Disk massesa
RMS massesb
20 K 40 K 50 K
[M⊙] [MJup]
HH 666 0.77 0.38 0.30 6.14
HH 900 A 0.43 0.21 0.17 3.72
HH 900 B 0.05 0.02 0.02 3.72
HH 1004 A 0.38 0.19 0.15 4.58
HH 1004 B 0.04 0.02 0.01 4.58
HH 1004 C 0.07 0.03 0.03 4.58
HH 1006 0.48 0.24 0.19 4.32
HH 1010 0.21 0.10 0.08 8.39
HH 1066 0.19 0.09 0.07 4.58
a We estimate different mass values by varying the assumed tem-
perature to compare the mass variation.
b Masses estimated from image noise at 4σ.
Table 2. Dust masses obtained by the emission detected at
1.3 mm for the compact systems (discs+envelopes) associ-
ated to each HH object studied.
that corresponds to an approximate physical size of 200
au × 150 au, which is according to the physical sizes of
the protoplanetary disks (∼100 au).
From this detected dust emission, we can estimate the
total mass for these structures, even for the case of com-
ponent B, which is much fainter than component A. At
millimeter wavelengths, the emission can be assumed to
be optically thin, and we can then estimate the dust
mass from the following expression:
Md =
D2
Sν
κν Bν(Td)
(1)
where Sν is the flux density, D is the distance to the
considered sources, we assume that it is the same as
the Carina Nebula (2.3±0.1 kpc, Smith & Brooks 2008),
κν= 0.015 cm2
g−1
is the dust mass opacity for a dust-
to-gas ratio of 100 appropriate for 1.3 mm (Ossenkopf
& Henning 1994) and Bν(Td) is the Planck function for
the dust temperature Td. Given the observing frequency
of our data (∼ 225 GHz), we considered the Rayleigh-
Jeans regime. We compute the values for the masses of
this (and the others) source and show them in Table 2
from the measured fluxes presented in Table 1. For this
source, we found that the dust mass associated with the
detected continuum structure (∼ 15 mJy) is between
0.3−0.7 M⊙, assuming temperature values between 20
K and 50 K as Cortes-Rangel et al. (2020).
As mentioned earlier, we also show the molecular
CO(2−1) emission corresponding to the outflow in the
HH 666 object. In Figure 1, we can see the molecu-
lar emission plotted in blue and red colors correspond-
ing to the blueshifted and redshifted gas, respectively.
5. 5
From these maps, we only detected CO(2−1) emission
(blueshifted+redshifted) toward the western side of the
ALMA 1.3 mm continuum source, revealing a monopo-
lar outflow, which is associated with the extended HH
666 object. We did not detect molecular CO(2−1) emis-
sion associated with the large globule itself, maybe be-
cause its emission is either extended and complex, so our
ALMA observations could not recover quite well the ex-
tension of the globule. Another possibility is that this is
an old globule with a quite small quantity of molecular
gas. Klaassen et al. (2019) using ALMA Compact Array
(ACA) observations of pillar 3 (corresponding to the HH
666 globule) reported clumpy and dispersed CO(2−1)
emission. Despite the larger beamsize of their obser-
vations with respect to ours (i.e. 6 arcsec or about 20
times larger), the extended emission of the globule was
poorly recovered, we then favor the interpretation that
our observations are losing most of the extended emis-
sion.
Since the detected CO emission is faint, it is difficult to
say anything about the orientation, extension, or mor-
phology of the molecular outflow. From Figure 1, this
appears to have a West to East orientation with mostly
the compact emission arising towards the western side.
In addition, we cannot give an estimation for the mass of
the globule, and its respective outflow due to not tracing
their complete structure.
3.2. HH 900
HH 900 is a dark globule located very close to the
central zone of the Carina Nebula, a region strongly af-
fected by the extreme UV radiation generated by nearby
massive stars to the star cluster Trumpler 16, and the
massive and evolved variable star η Carinae located
about ∼3 pc from the HH 900. It has an angular size
of the order of 1′′
(equivalent to a spatial scale of ∼0.01
pc). This source is also known as the tadpole due to its
unusual morphology that simulates a baby frog, made
up of a dense globule (tadpole head) followed by an
elongated and compact tail that extends in the same
direction as the axis of the optical jet revealed by the
images of the HST (see Figure 2). Using these observa-
tions, Smith et al. (2010) studied the components of the
bipolar structure of the optical jet, and globule traced
by the gas emission of Hα corresponding to externally
ionized gas. The asymmetric morphology revealed at
optical wavelengths has not been explained since it
differs from the typical jet morphologies that present
a collimated and very symmetrical bipolar structure
(Reipurth & Bally 2001; Reipurth et al. 2019; Noriega-
Crespo et al. 2020). The extreme UV radiation field is
illuminating throughout the length of the protostellar
jet with a projection close to the plane of the sky and an
inclination angle for the jet ∼ 10◦
(Reiter et al. 2015b).
They studied the high-velocity component of the pro-
tostellar jet through near-infrared (NIR) observations
for the line of [Fe II] and that, unlike the observations
of Hα, showed an external collimated jet structure that
is extending from east to west of the globule, presenting
a remarkable symmetry that argues for the fact that the
driving source would have to be located inside the cen-
ter of the globule although they did not find IR emission
from the protostar inside the globule, suggesting the fact
that the protostar may be embedded inside remaining
invisible due to the high column density. Shinn et al.
(2013) detected two sources associated with the HH 900
object through observations of [Fe II] at 1.64 µm but un-
til now, no study could corroborate that these detected
sources were generating the jets because no direct con-
nection was found between the extended flows and the
compact sources detected by this study (YSO also cat-
aloged by Spitzer, Povich et al., 2011).
Subsequently, Reiter et al. (2019) studied the HH 900
source at optical wavelengths with MUSE/VLT obser-
vations detecting several emission lines (hydrogen re-
combination lines and some forbidden emission lines)
that also trace the outflow. Their observations were
also unable to detect the protostar embedded within the
tadpole, although the emission was detected for different
lines that are tracing the collimated bipolar jet at dif-
ferent densities (for example [Fe II], [Ca II], and [Ni II]),
is emanating from the globule, which reinforces the idea
of that the protostellar source must be housed inside it.
More recently Reiter et al. (2020a) reported us-
ing ALMA observations the bipolar molecular outflow
traced by the CO emission arising from the proto-
star called HH 900 YSO. The outflow is bi-conical and
matches very well the overall morphology of the optical
jet. The estimated mass for the total globule is about
2 M⊙ (from the dust continuum), which results in a
lifetime of 4 Myrs of Reiter et al. (2020a), with the as-
sumption of a constant photo-evaporation rate.
Our results obtained from the ALMA observations for
the continuum emission at 1.3 mm reveals two compact
sources called A and B (white contours in Figure 2).
These two compact objects were already reported in
previous ALMA observations presented in Reiter et al.
(2020a). The millimeter emission is shown in Figure 2
as white contours and is likely associated with the dust
emission of the circumstellar envelope and flatted disk
(see for example Reiter et al. (2020a,b)). We note that
the emission is located at the center of the tadpole’s head
from which emerges the bipolar molecular outflow also
6. 6
Source Pillar/Globule Outflowa
Iν
b
dvc
Sized
Mass Ired,
ν
e
Iblue
ν dvred,f
dvblue
Sizered
Sizeblue
Massg
[ mJy
beam
] [km s−1
] [arcsec2
] [M⊙] [ mJy
beam
] [km s−1
] [arcsec2
] [M⊙]
HH 900 60 2.7 5.2 4×10−3
46.9 23.5 3 1 2 2 1.4×10−3
HH 1006 50 3.2 11.4 7×10−3
44 17.6 3 2.5 3.2 1.2 2.1×10−3
HH 1010 50 2.2 170 7×10−2
3.3 4 4 2 2.5 0.25 1.5×10−3
a Red and blue superscript refer to detected redshifted and
blueshifted gas.
b Average intensity for the pillar or globule.
c Velocity range for the pillar or globule flux.
d We obtain the size by multiplying θmax × θmin.
e Average intensity for the outflow.
f Velocity range for the outflow flux.
g It is the total mass of the outflow, that is, the sum of the mass
of the redshifted and the blueshifted outflow.
Table 3. Gas masses obtained by the emission detected for the CO(2−1) emission at 230 GHz for the pillars/globules and
outflows associated with each HH object studied. We estimate the mass using an excitation temperature of Tex=50 K, an
abundance ratio between the molecular hydrogen and CO of X H2
CO
∼104
, and a distance to Carina nebula of 2.3 kpc. We only
included the sources for which there was CO molecular detection.
HH 900
ALMA + HST
A
B
Tr 14
Tr 16
Tr 16
5000 au
Figure 2. A combined HST (optical) + ALMA (radio) image is shown for the globule HH 900. The optical image (green) is the
Hα emission about the optical jet and obscured globule that houses the protostellar source evidenced by 1.3 mm emission (white
contours varying from 30% to 90% of the peak emission, in steps of 10%). The peak of the millimeter continuum emission is
2.41 mJy beam−1
for component A and 0.75 mJy beam−1
for component B. Also shown in blue and red colors is the CO(2−1)
moment zero for the molecular outflow associated with the protostar (component A). Component B does not have any associated
molecular outflow. In this case, the blue color corresponds to the blueshift molecular gas, and the red color corresponds to the
redshift molecular gas. The LSR system velocity of the globule is about −33.72 km s−1
. The white arrow indicates the direction
where the star clusters Tr 14 and Tr 16 are located.
7. 7
detected thanks to the high angular resolution of ALMA
Reiter et al. (2020a). Our observations also revealed
a second component traced by the continuum emission
(component B) located in the southeastern part of the
optical jet in the area strongly illuminated by external
ultraviolet radiation. From the Figure, we can see that
there is no molecular outflow associated with this com-
ponent, maybe because this source is prestellar, as al-
ready discussed in Reiter et al. (2020a). Reiter et al.
(2019) also rejected the premise that this detected ob-
ject (named PCYC 838) was driving a microjet. They
dismissed the idea by arguing that the symmetric [Fe II]
jet is centered on the globule and not the star, in ad-
dition to the lack of evidence of different velocity com-
ponents in the reported spectra, concluded that a likely
explanation is that this object is coincidentally aligned
with the observed jet.
From the continuum emission, we obtained an inte-
grated flux of 8.37 ± 0.61 mJy and 1.09 ± 0.09 mJy for
components A and B respectively, and an observed rms
noise of 0.043 mJy (see Table 1). From the synthesized
beam size (0′′
.34 × 0′′
.27), we obtained a deconvolved
size for component A of 0′′
.576 ± 0′′
.052 × 0′′
.396 ±
0′′
.042 with an PA of 155◦
± 12◦
, with an approximate
physical size of 1330 × 910 au.
From the millimeter continuum emission, we estimate
the dust mass associated with the structure detected
by our observations, following the equation described
in the previous subsection (1), giving values between
0.17−0.43 M⊙, assuming temperatures between 20 K
and 50 K for the component A, which is the component
associated with the detected CO(2-1) bipolar molecular
outflow shown in red and blue colors in the Figure 2.
This line emission at 230 GHz is tracing perfectly the
tail of the tadpole (blueshifted CO gas) extending along
the axis of the optical jet, just like its counterpart (red-
shifted CO gas). We can deduce that the protostar is
a Class 0/I object from the mass-loss rate (∼ 5× 10−6
M⊙ yr−1
) reported by Reiter et al. (2015b). The con-
tinuum emission of this source possibly includes the disk
and envelope, which reveals the emission from the disk
and the envelope around the driving source. For com-
ponent B we estimated a dust mass between 0.02−0.05
M⊙ under the same assumptions.
We note in Figure 2 that the molecular outflow is
aligned to the optical jet, and expands at velocities be-
tween −32 and −36 km s−1
. The flux detected in CO
is tracing the innermost parts of the dark globule con-
nected to the extent of the outflow with the driving
source detected by the continuum emission. We inte-
grate LSR velocities from −29.27 to −33.08 km s−1
for
the redshifted emission oriented to the northwest, and
CO(2-1)
HH 900
HH 900
C18O(2-1)
Figure 3. The upper panel shows the moment zero (con-
tours) and moment one (colors) for CO(2−1), and the lower
panel shows the moment zero (contours) of CO and moment
one (colors) of C18
O (2−1) of the globule HH 900. The
contours vary in the range from 40% to 90% of the peak
emission, in steps of 12%. The peak of the CO (2−1) emis-
sion is 0.33 Jy Beam−1
km s−1
. The arrows (blue and red)
show the direction of molecular outflow expansion. The gray
circles in both figures represent the location of the compact
source (system disk+envelope) detected in the continuum at
1.3 mm. The LSR radial-velocity scale bar is shown on the
right.
from −34.99 to −40.70 km s−1
for the blueshifted emis-
sion oriented to the southeast, for the CO outflow in
the HH 900 object. The molecular outflow revealed by
the CO is only evident for one component denominated
component A.
In Figure 3, we show the emission of molecular gas
for the CO(2−1) (top panel) and C18
O(2−1) (bottom
panel) detected lines. The moment zero of CO is shown
in black contours for both panels of Figure 3, as a com-
parison between the emission of the molecules. The mo-
ment one is shown in color scale for CO (top panel)
and for C18
O (bottom panel). It is observed that CO is
perfectly tracing the globule, including the tail of the
globule, hosting the compact source detected by the
continuum (gray circle) and corresponding to the bipo-
8. 8
lar molecular outflow of CO also observed. The bipo-
lar molecular outflow is also evident in these maps for
both panels, with a northwestern orientation to the red-
shifted emission and a southeastern orientation to the
blueshifted emission. If we analyze the velocities for the
molecular outflow in this map, we note that the width
velocity is ∼ 5 km s−1
, which suggests that the molecu-
lar flow is not a high velocity one.
The outflow extends no further than the emission de-
tected for the rest of the HH 900 globule (bounded by
the moment zero of CO). The different velocity compo-
nents detected vary between the LSR range of −29.27
to −40.70 km s−1
, velocities that were used to integrate
the moment zero (contours) and one (colors) of the CO
emission. The average LSR velocity of the cloud is ∼
−34 km s−1
. The CO molecule best traces the globule
as a whole, while the C18
O is evidencing more internal
zones of the cloud where the protostar and envelope are
localized, and the density is higher. This image (bottom
panel) was obtained by integrating over the LSR veloc-
ity range of −33.23 to −35.23 km s−1
. The system LSR
velocity of the cloud is ∼−33.90 km s−1
. For this case,
the molecular emission shows a width of velocities ∼ 1
km s−1
, which confirms the result obtained with the CO
map showing that these flows are not high speed.
We compute the gas mass using the observed CO tran-
sition J=2 → 1 from the following equation:
MH2
M⊙
= 1.2 × 10−15
Tex e
16.59
Tex X H2
CO
R
Iνdv
Jy km s−1
θmaj θmin
arcsec2
D
pc
2
,
(2)
where X H2
CO
∼104
(Scoville et al. 1986) is the abundance
ratio between the molecular hydrogen (H2) and carbon
monoxide (CO), Iν is the average intensity (Iν) for the
pillar-globule/outflow, dv is the velocity range for the
pillar-globule/outflow, D is the distance to the source
of 2.3±0.1 kpc and Tex is the excitation temperature
taken as 50 K, this is the highest temperature in the
range used previously for the dust temperature, and it
provides an upper limit for our mass estimation.
We obtained a value for the gas mass of the tadpole
globule of 4 × 10−3
M⊙ using the emission lower than
±1 km s−1
from the system velocity, and the mass of
the outflow was 1.4 × 10−3
M⊙ for velocities larger than
±1 km s−1
(see table 3). The estimated values for both
masses should be considered as a lower mass limit be-
cause the medium could be optically thick.
We calculate the theoretical value of the mass photo-
evaporation rate (Ṁ) for the globule HH 900 associated
with the driving source following Cortes-Rangel et al.
Source R a
Ṁb
tc
[au] [M⊙ yr−1
] [yr]
HH 900 8050 2.6×10−5
153
HH 1006 8740 5.7×10−6
1228
HH 1010 39100 3.1×10−5
2258
a Radius of the pillarglobule
b Mass photoevaporation rate
c Photoevaphoration timescale
Table 4. The sizes of each pillar/globule were calculated us-
ing a Gaussian fitting in CASA to the extended gas emission
using CO (2−1), assuming a distance of 2.3 kpc to each of
the studied sources. Each pillar/globule is affected by ultra-
violet radiation (FEUV ) originating from the nearby clusters,
Tr 14 and Tr 16, for which a UV luminosity of approximately
(QH ) = 2×1050
photons s−1
for Tr 14 and (QH ) = 9×1050
photons s−1
for Tr 16 (Smith Brooks 2008).
(2020) (see their equation 3). The size of the globule
was calculated using a Gaussian fitting in CASA, as-
suming a distance of 2.3 kpc. In this case, the globule is
affected by ultraviolet radiation originating from the Tr
16 with a UV luminosity of (QH) = 9×1050
photons s−1
(Smith Brooks 2008). This luminosity (QH) trans-
lates into a flux FEUV = 8.35 × 1011
photons s−1
cm−2
assuming that the distance from the HH 900 globule
to the cluster is ∼ 3pc. We obtained a mass photo-
evaporation rate of 2.6×10−5
M⊙ yr−1
. This estimated
value is consistent with the methodology described by
Reiter et al. (2015b) (7 × 10−6
M⊙ yr−1
), taking into
account that we have used the gas mass of the globule
(instead of the dust mass) which translates into a dif-
ference of at least an order of magnitude in mass and
a factor of ∼4 in size, so our value differs by an order
of magnitude than the one presented by them. In this
calculation we do not consider the optical depth value
and since the globule is very optically thick that may
account for the difference. We can estimate the photo-
evaporation timescale of the globule HH 900 by dividing
the estimated gas mass for the globule (4 × 10−3
M⊙)
by this mass photo-evaporation rate, giving ∼ 150 yr,
which will be the time in which the globule HH 900 will
be photo-evaporated by the massive stellar cluster Tr
16 (see Table 4). Using the dust mass we estimated for
this globule (0.21 M⊙), that corresponds to the whole
continuum emission at 1.3 mm, the photo-evaporation
timescale would be ∼8000 yr, ∼two orders magnitude
less than the reported value reported by Reiter et al.
(2020a) (4 Myr), although it should be noted that our
estimated dust mass differs by a factor of ∼10 and the
photo-evaporation rate by a factor of ∼100.
3.3. HH 1004
9. 9
Tr 16
HH 1004
ALMA + HST
A
B
C
3500 au
3500 au
Figure 4. A combined (optical+radio) HST and ALMA image is shown for the pillar HH 1004. The optical image, in green, is
the Hα emission and is showing the optical jet and the pillar in which the compact source detected in the continuum at 1.3 mm
is embedded and shown as white contours (varying from 15% to 90% of the peak emission, in steps of 10%). Three compact
sources were detected (components A, B, and C). The peak of the millimeter continuum emission is 3.51 mJy Beam−1
but there
is still extended emission at lower levels. Also shown in blue and red colors is the CO(2−1) moment zero for the molecular
outflows associated with the compact sources. In this case, the blue color corresponds to the blueshift molecular gas and the
red color corresponds to the redshift molecular gas. The LSR system velocity of the globule is about −20 km s−1
. The white
arrow indicates the direction where the star cluster Tr 16 is located.
This source is located in the southern region of the Ca-
rina Nebula, specifically within the South Pillars. The
pillar identified by Smith et al. (2010) exhibits a highly
elongated structure pointing towards the Tr 16 stellar
cluster. This displays a clear optical bipolar jet at the
tip of the pillar, which is being strongly irradiated by the
UV radiation field emanating from the OB stars present
in Tr 16. Further south of the pillar, the presence of
another bright jet is evident, expanding in a southwest
direction opposite to that of the stellar cluster. There
are shock structures further away that may potentially
be associated with the same jet phenomenon, although
considering only the innermost part of the detected opti-
cal jet, a jet length of approximately 0.4 pc is quantified.
In Figure 4, the combination of observations made
with HST/ACS for the HH 1004 pillar and our observa-
tions obtained with ALMA for the continuum and CO
emission are shown. The optical image (green) corre-
sponds to the Hα emission and is overlapped with the
ALMA high velocity CO(2−1) molecular emission (blue
and red), and the 1.3 mm continuum emission (white
contours). The CO(2−1) molecular emission was ob-
tained by integrating in LSR velocities from −15.55 to
−4.75 km s−1
for the redshifted emission, and from
−40.31 to −25.07 km s−1
for the blueshifted emission.
The ALMA 1.3 mm continuum image reveals three com-
pact sources (A, B, and C) distributed in the northern
region of the pillar (at the head of the pillar, see Table
1). Components A and B appear to be associated with
the optical jet detected in Hα.
For this millimeter continuum emission, we obtained
an integrated flux of 7.42 ± 0.38 mJy for source A, 0.90
± 0.15 mJy for source B, and 1.49 ± 0.09 mJy for source
C respectively. The observed rms noise was 0.053 mJy
for the three sources, which is very close to the theo-
retical noise value (see Table 1). From the synthesized
beam size (0′′
.11 × 0′′
.06), we obtained a deconvolved
size similar to HH 666, for example, for source C we ob-
tained a deconvolved size of 0′′
.036 ± 0′′
.014 × 0′′
.017
± 0′′
.018 with an PA of 178◦
± 49◦
, that corresponds to
10. 10
Tr 16
HH 1006
ALMA + HST
8500 au
Figure 5. The figure shows a combined (optical+radio) HST and ALMA image for the globule HH 1006. The optical image
(green) is the Hα emission and is showing optical jet and the globule in which the compact source detected in the continuum at
1.3 mm is embedded, and shown as white contours (varying from 55% to 90% of the peak emission, in steps of 10%). The peak
of the millimeter continuum emission is 7.83 mJy beam−1
. Also shown in blue and red colors the CO(2−1) moment zero for
the molecular outflows associated with the compact source. In this case, the blue color corresponds to the blueshifted molecular
gas and the red color corresponds to the redshifted molecular gas. The LSR system velocity of the globule is about −23 km
s−1
. The white arrow indicates the direction where the star cluster Tr 16 is located.
an approximate physical size of 83 au × 40 au, consis-
tent with the typical physical sizes of the protoplanetary
disks (Andrews 2020).
We estimated the total masses for these structures us-
ing the equation 1 and we obtained that the masses
for components A, B, and C are between 0.15−0.38,
0.01−0.04 and 0.03−0.07 M⊙ respectively, assuming
temperature values between 20 to 50 K (see Table 2).
We show in the same Figure 4, the molecular CO
(2−1) emission plotted in blue and red colors corre-
sponding to the blueshifted and redshifted gas, respec-
tively. We observe a bipolar outflow emerging from the
compact continuum source A, with the blueshifted por-
tion extending southwest along the axis of the optical
jet detected in Hα. Very little redshifted emission is
apparent, and due to the weak flux detected at these
velocities, it is not clear whether this emission expands
in the same northeast direction along the axis of the op-
tical jet. Source B also appears to overlap a portion of
the blueshifted molecular outflow detected, although it
is difficult to discern whether the detection of this molec-
ular outflow is generated by both sources A and B, or if
it is solely attributed to source A, which is larger (∼230
au × 140 au) and more massive (0.38 M⊙) compared to
11. 11
HH 1006
CO(2-1)
C18O(2-1)
HH 1006
Figure 6. Images of moment zero (contours) and moment
one (colors) are presented for the molecular emission of CO
(2−1) (top panel), and moment one of C18
O (2−1) (bottom
panel) of the globule of HH 1006. The Figure presents a com-
parison between the CO moment zero presented in contours
(varying in the range from 1% to 90% of the peak emission,
in steps of 10%), by the emission that is best tracing the
globule, with respect to the moment one of emission for CO
and C18
O. The peak of the millimeter line CO emission is
0.71 Jy Beam−1
km s−1
. The arrows (blue and red) show
the direction of molecular outflow expansion. The gray cir-
cles in both Figures represent the location of the compact
source (system disk+envelope) detected in the continuum at
1.3 mm. The LSR radial-velocity scale bar is shown on the
right.
source B (∼140 au × 100 au, 0.04 M⊙ mass). Compact
source C exhibits a CO redshifted molecular outflow that
is more extended than the one detected for sources A
and B, although it does not display a blueshifted coun-
terpart. This can be explained by the inhomogeneities
in the cloud. As far as we know this is the first molecu-
lar detection for this outflow component. This source is
north of the [Fe II] emission that goes through the pillar
(see Fig 6 in Reiter et al. (2016)). This looks to be in
the right place to drive the extended Hα emission seen
off the left of the pillar that Smith et al. (2010) identify
as HH 1005.
3.4. HH 1006
This bipolar jet emerges from a small dark globule,
pointing in the northern direction of η Carinae, and is
located in the central region of the South Pillars in the
zone where these pillars are strongly irradiated by the
massive stars of Tr 16. The HH 1006 jet is formed by
a chain of knots that extend along its axis, and have an
extension of ∼0.2 pc measured in optical wavelengths by
Smith et al. (2010), and by Sahai et al. (2012), who pre-
sented CO (3−2) single dish observations, although for
our study we have focused only on the characterization
of the central jet, that is, the closest to the globule.
In Figure 5 we show an optical image of the HST in Hα
(green), and our results obtained with the ALMA ob-
servations for the continuum emission at 1.3 mm (white
contours in the Figure) and the CO molecular emission
(red and blue colors). The continuum emission reveals a
compact source at the center of the globule with an in-
tegrated flux of 9.41 ± 0.73 mJy and a PA of 43◦
± 17◦
(see Table1). From the synthesized beam size (0′′
.23
× 0′′
.20), we obtained a deconvolved size of 1′′
.139 ±
0.′′
089 × 0.′′
945 ± 0′′
.075, which corresponds to an ap-
proximate physical size of 2600 au × 2200 au. The com-
pact source is generating the molecular outflow that ex-
tends along the same axis of the globule. We estimate
that the mass of dust follows again the equation (1) and
is between 0.19−0.48 M⊙, assuming temperature values
between 20 K and 50 K. This value is an order of mag-
nitude lower than the estimation of 0.02 M⊙ obtained
by Mesa-Delgado et al. (2016), which can be explained
by the fact that we report a larger source size. Perhaps,
we are detecting more of the envelope than they did.
The molecular outflow is detected aligned on the axis
of the optical jet and extending in the same direction of
the globule axis at velocities between −21 and −24 km
s−1
. This CO flux is tracing the innermost parts of the
globule connected to the extent of the outflow with the
driving source. We integrate in radial velocities from
−17.88 to −21.05 km s−1
for the redshifted emission
oriented to the south, and from −24.23 to −27.40 km
s−1
for the blueshifted emission oriented to the north of
the globule.
In Figure 6, we show the moment zero map ob-
tained from CO(2−1) in contours overlaid with mo-
ment one map obtained from CO(2−1, upper panel) and
12. 12
HH 1010
Tr 14
ALMA + HST
8500 au
Figure 7. ALMA CO(2−1) moment zero (blue and red colors) and millimeter continuum (white contours) images of the HH
1010 object overlaid in a HST (Hα) optical image (green colors). The blue and red colors represent the blueshifted and redshifted
CO emissions, respectively, from the HH 1010 outflow. The 1.3 mm continuum emission is denoted by the white contours. The
contour levels range from 18% to 90% of the peak emission, in steps of 10%. The peak of the millimeter continuum emission
is 4.07 mJy Beam−1
. Here, we are only contouring the most compact 1.3 mm emission from our observations revealing the
envelope and the disk. We integrate in radial velocities from −9.54 to −15.25 km s−1
for the redshifted emission, and from
−18.43 to −27.32 km s−1
for the blueshifted emission for the CO outflow in the HH 1010 object. The LSR system velocity of
the entire pillar associated with the object HH 1010 is about −16.52 km s−1
.
13. 13
HH 1010
CO(2-1)
C18O(2-1)
HH 1010
Figure 8. Images of moment zero (contours) and moment
one (colors) are presented for the molecular emission of CO
(2−1) (top panel) and the moment one of C18
O (2−1) (bot-
tom panel) of the globule of HH 1010. The Figure presents
the CO moment zero emission in contours varying from 3%
to 90% of the peak emission, in steps of 10%. The peak of the
millimeter line CO emission is 1.2 Jy Beam−1
km s−1
. The
arrows (blue and red) show the direction of molecular out-
flow expansion. The gray circles in both figures represent the
location of the compact source (system disk+envelope) de-
tected in the continuum at 1.3 mm. The LSR radial-velocity
scale bar is shown on the right.
C18
O(2−1, bottom panel), respectively. It is observed
that CO is perfectly tracing the globule hosting the com-
pact source detected by the continuum (gray circle) and
corresponding to the center of the bipolar molecular out-
flow also evident in the top panel. The width velocity
is ∼ 5 km s−1
, which tells us that the molecular out-
flow is not high velocity one. The CO moment zero for
the top panel image was obtained by integrating in the
LSR velocity range of −17.88 to −27.40 km s−1
. The
system LSR velocity of the cloud is ∼ −23 km s−1
. The
CO is the best tracer of the globule, while the C18
O
traces more internal zones of the cloud where the proto-
star and envelope are localized. The bottom panel image
was obtained by integrating over the LSR velocity range
of −21.93 to −24.60 km s−1
with a width of velocities
∼ 1 km s−1
.
The gas mass of the globule is 4 × 10−3
M⊙ and the
mass of the outflow is 2.1 × 10−3
M⊙ (see Table 3). The
globule HH 1006 is affected by the UV radiation coming
from the cluster Tr 16, which has a UV luminosity of
(QH) = 9×1050
photon s−1
, and given the distance at
which the source of the cluster is located (∼16 pc), we
obtain a flux FEUV = 3.09×1010
photons s−1
cm−2
. We
obtained a mass photoevaporation rate of 5.7×10−6
M⊙
yr−1
and the photoevaporation timescale of the globule
HH 1006 given the estimated mass of gas (7 × 10−3
M⊙)
is ∼1230 yr (see Table 4).
3.5. HH 1010
This source emerges from the tip of a giant dark pillar
located at the western periphery of the Carina nebula,
and pointing toward the evolved star η Carinae and Tr
16. Smith et al. (2010) detected optical emission within
the pillar, although their detection could not be corrob-
orated. From the optical images, the presence of a bipo-
lar jet becomes evident, also reported by McLeod et al.
(2016), with its jet axis perpendicular to the pillar axis.
This geometrical configuration is commonly observed in
Carina Pillars.
In Figure 7, we show an optical image of the HST in
Hα (green), and our results obtained with the ALMA
observations for the continuum emission at 1.3 mm
(white contours) and the CO (2−1) molecular emission
(red and blue colors). The continuum emission reveals a
compact source at the center of the pillar head, and that
is exciting the molecular outflow. This outflow extends
along the jet axis at velocities between −9 and −27 km
s−1
. This continuum emission has an integrated flux of
4.12 ± 0.17 mJy. We were not able to resolve the source
because the angular resolution was not sufficient (see
Table 1).
The dust mass for the continuum source is between
0.08−0.21 M⊙, assuming temperature values between
20 and 50 K. The CO is tracing the outflow and was
obtained by integrating the emission in radial velocities
from −9.54 to −15.25 km s−1
for the redshifted emission
oriented to the south, and from −18.43 to −27.32 km
s−1
for the blueshifted emission oriented to the north
of the pillar. Red/Blueshifted distribution is consistent
with McLeod et al. (2016) observations.
14. 14
ALMA + HST
HH 1066
Tr 14
8500 au
A
B
Figure 9. This image is a combination of a HST (optical) + ALMA (radio) image for the globule HH 1066 located in The
Mystic Mountain in Carina. The optical image (green) is the Hα emission from the optical jet and obscured globule that houses
the protostellar compact source traced by ALMA 1.3 mm continuum emission (white contours varying from 50% to 90% of the
peak emission, in steps of 10%). The peak of the millimeter continuum emission is 1.96 mJy Beam−1
. We also show the C18O
(2−1) moment zero (blue and red colors) for the molecular outflow associated with the protostar. The blue color corresponds
to the blueshifted molecular gas and the red color corresponds to the redshifted molecular gas. The LSR system velocity of the
globule is about −9.18 km s−1
. The white arrow indicates the direction where the star cluster Tr 14 is located.
In Figure 8, we show the emission of molecular gas
for the CO (2−1) and C18
O (2−1) transitions. The mo-
ment zero (black contours) represents the CO emission
in both panels. The moment one is presented (in colors)
for the CO (top panel) and C18
O (bottom panel). For
the top panel, the CO moment zero image was obtained
by integrating in the velocity range of −9.54 to −27.32
km s−1
, with the average LSR velocity of the cloud ∼
−16 km s−1
. The bottom panel image was obtained by
integrating over the velocity range of −15.65 to −18.65
km s−1
km s−1
, with the average LSR velocity of the
cloud ∼ −17 km s−1
. We note the fact of the CO is
tracing perfectly the pillar in all its extension and the
accurate shape of the molecular outflow is still evident
even considering all the CO emission. The C18
O is again
tracing zones deep inside the cloud, where the protostar
is forming and therefore the density is higher.
The estimated gas mass for the HH 1010 object is 7 ×
10−2
M⊙ and the mass of the outflow is 1.5 × 10−3
M⊙
(see Table 3). The globule HH 1010 is affected by the UV
radiation coming from the cluster Tr 14, given the dis-
tance at which the source of the cluster is located (∼13
pc), we obtain a flux of FEUV = 1.02×1010
photons s−1
cm−2
, and the mass photoevaporation rate 3.1×10−5
15. 15
HH 1066
C18O(2-1)
HH 1066
N2D+(3-2)
Figure 10. Images of moment zero (contours) and moment
one (colors) are presented for the molecular emission of C18
O
(2−1) (top panel) and moment one of N2D+
(3−2) (bottom
panel) of the globule of HH 1066. The C18
O moment zero
presents the emission in contours varying from 10% to 90% of
the peak emission, in steps of 15%. The peak of the millime-
ter line C18
O emission is 0.11 Jy Beam−1
km s−1
. The gray
circles in both figures represent the location of the compact
source (system disk+envelope) detected in the continuum at
1.3 mm. The LSR radial-velocity scale bar is shown on the
right.
M⊙ yr−1
, yielding a photoevaporation timescale ∼2260
yr (see Table 4).
3.6. HH 1066
This object was detected to the west of the Carina
nebula very close to the Tr 14 star cluster just above
the HH 901 and 902 sources, which all together form
the structure known as The Mystic Mountain1
. The de-
tected jet is approximately 0.05 pc in extent and is asso-
ciated with what appears to be a small, bright bow shock
(see Smith et al. 2010) although without an obvious op-
tical jet counterpart. Through optical observations (Hα)
they were able to detect a weak point source of emission
located at the tip of the dark cloud and within the axis
of the optical jet, which was also detected with IR obser-
vations of Spitzer (YSO detected along the optical jet,
see Povich et al. 2011) without a clear association with
the driving source. Further optical and IR observations
Reiter Smith (2013) made evident the bipolarity of
the collimated jet detected in Hα and [Fe II] but again
without being able to evidence the complementary bow
shock.
In Figure 9, we show an optical image from the HST
(in Hα, in green) and our results obtained with ALMA
observations for the continuum emission (at 1.3 mm in
white contours) and the C18
O molecular emission (red
and blue colors). In this case, it was not possible to
highlight the outflow with CO(2−1) emission due to con-
tamination of ambient gas, and the structures near the
globule. Although we tried to reproduce the innermost
zone (blue and red colors) of the C18
O molecular out-
flow (in the previous cases where we have used CO),
the emission plotted in Figure 9 only represents the in-
nermost zones of the molecular cloud, without clearly
outlining the outflow. The emission in this case was in-
tegrated over the LSR velocity range of −7.51 to −8.18
km s−1
for the redshifted gas and −9.84 to −10.18 for
the blueshifted gas.
From the continuum emission, we detected a compact
dust source associated with the envelope and disk struc-
ture, where the protostellar source is embedded (com-
ponent A, see Figure 9), and a compact emission source
(component B). For component A, we obtained an in-
tegrated flux of 3.86 ± 0.66 mJy, and a rms noise of
0.05 mJy (see Table 1). From the synthesized beam
size (0′′
.26 × 0′′
.18), we obtained a deconvolved size of
0.′′
373 ± 0.′′
085 × 0.′′
211 ± 0.′′
092, with a PA of 170◦
±
26◦
, which corresponds to an approximate physical size
of 850 × 490 au. We estimated the dust mass from
the continuum emission and obtained values between
0.07−0.19 M⊙, varying the temperature between 20 and
50 K, these values are in agreement with the estimated
values by Mesa-Delgado et al. (2016) (they estimated
the mass ∼ 0.04M⊙), we clearly are recovering some ex-
tended emission. Additionally, we report for the first
1 https://hubblesite.org/contents/media/images/2010/13/2707-
Image.html?news=true
16. 16
time the detection for component B, whose integrated
flux of 2.9 mJy and peak flux of 0.8 mJy, are about an
order of magnitude larger than rms value. There was no
gas detection associated with this component.
In Figure 10, we show the moment zero obtained from
the C18
O (2−1) (contours) combined with moment one
image obtained from the C18
O (2−1) (upper panel)
and N2D+
(3−2) (bottom panel) emissions, respectively.
This is the only source in this study where we detected
N2D+
(3−2) emission. The moment zero image of C18
O
perfectly traces the globule of HH 1066, and it does not
extend beyond the boundary delimited by the optical
emission detected in Hα (see Figure 9). The moment
one reveals gas kinematics, that for C18
O, evidences a
small velocity gradient with ranges between −7 to −10
km s−1
, with higher velocities toward the outer walls
of the globule. In the case of N2D+
moment one, the
velocities vary over a smaller range from −8 to −9 km
s−1
, and the structure traced by the gas is located in
the innermost regions of the globule, close to the proto-
stellar source detected by the continuum emission (gray
circle).
3.7. Planet Formation
We can examine if the results obtained for the com-
pact disks+envelopes revealed in our 1.3 mm continuum
maps for the HH objects are in principle consistent with
the formation of planets. If we consider the lowest value
obtained for the masses of the disks+envelopes (0.01
M⊙ for HH 1004 component B) which corresponds to
∼ 10 MJup, we can see that is above the minimum re-
quired mass (10 MJup) for a pre-solar nebula to develop
a planetary system (Weidenschilling 1977). However,
we remark that there is probably contamination of the
dusty envelope, so the mass of the disk could be lower.
However, if we consider the maximum mass value ob-
tained (0.77 M⊙ for HH 666), corresponding to ∼ 800
MJup, we see that it is well above the minimum required,
which is the case for many other sources detected with
our observations, so at least in most of the sources this
minimum mass condition is fulfilled.
On the other hand, a second important factor to con-
sider is the average age of the Carina population which
is ∼1–4 Myr (Smith Brooks 2008), consistent with the
minimum time-scale required to form planets ∼1–2 Myr
(see Hubickyj et al. (2005); Najita Kenyon (2014)).
The external UV irradiance from Tr 14 and Tr 16 could
photodisociate the material of the disks. However, these
disks are still very embedded within the globules and pil-
lars implying that they are not strongly irradiated yet.
All these conditions indicate the possibility that there
are young planets formed or in formation in these de-
tected disks.
4. CONCLUSIONS
In this work, we present a study of six pillars/globules
localized in the star forming region of Carina. We
used Atacama Large Millimeter/submillimeter Array
observations at 1.3 mm continuum, C18
O(2−1) and
12
CO(2−1) spectral lines with high angular resolution
and sensitivity. We have studied each source associated
with the Herbig-Haro objects, and their nearby environ-
ment, aiming to identify and analyze various character-
istics that are influencing each of the pillars/globules.
The most significant results derived from this study are
as follows:
i. For the first time, we have successfully identified
the millimeter compact sources associated with the
Herbig-Haro objects HH 666, HH 1004, HH 1006,
HH 1010, and HH 1066 along with the first detec-
tion of its component B. We also detected the CO
bipolar molecular outflows associated with these
continuum sources, extending along the optical jet
axis.
ii. From the observations, we have characterized the
objects from the morphological analysis of the
detected structures, revealing sizes of the pil-
lars/globules and of the detected continuum struc-
tures, for which we have concluded that, given
the sizes found (80−2600 au), they correspond to
structures associated with the dusty disks (∼100
au) and the envelope of the forming star, for which
we have also calculated the dust masses, finding
values between 0.01−0.7 M⊙. Between these val-
ues, planetary formation would be possible.
iii. We have also estimated the gas mass for the de-
tected molecular outflows from the CO emission,
giving values of 1.4×10−3
− 2.1× 10−3
M⊙, and
the same for the pillars/globules, which obtained
values of 7×10−3
− 7×10−2
M⊙. These estima-
tions only include the HH 900, HH 1006, HH 1010,
and HH 1066 sources since only for these we ob-
tained CO detection for the pillars/globules.
iv. We present the gas kinematics for the 12
CO and
C18
O molecular lines, estimations for the mass
photoevaporation rates for the HH 900, HH 1006,
HH 1010, and HH 1066 sources, with a range from
5.7 × 10−6
to 3.1 × 10−5
M⊙ yr−1
, indicating that
these pillars/globules will be photoevaporated on
time scales of the order of 150−2200 yr.
17. 17
This paper makes use of the following ALMA data:
ADS/JAO.ALMA#2017.1.00912.S ALMA is a part-
nership of ESO (representing its member states),
NSF (USA), and NINS (Japan), together with NRC
(Canada), MOST and ASIAA (Taiwan), and KASI
(Republic of Korea), in cooperation with the Repub-
lic of Chile. The Joint ALMA Observatory is oper-
ated by ESO, AUI/NRAO, and NAOJ. The National
Radio Astronomy Observatory is a facility of the Na-
tional Science Foundation operated under cooperative
agreement by Associated Universities, Inc. G.C.R. is
grateful to CONACyT, México, and DGAPA, UNAM
for the financial support. L.A.Z. acknowledges financial
support from CONACyT-280775 and UNAM-PAPIIT
IN110618, and IN112323 grants, México. P.R.R-O. ac-
knowledges support from the UNAM-PAPIIT IN110722
grant, CONACyT, México, and DGAPA, UNAM. The
HST data presented in this paper were obtained from
the Mikulski Archive for Space Telescopes (MAST) at
the Space Telescope Science Institute. The specific ob-
servations analyzed can be accessed via 10.17909/p1je-
9b56.
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