4. Galaxies: Some Key Questions
How were galaxies formed?
How do they evolve with time?
How does the environment influence their evolution?
What is the role of central supermassive black holes?
How can we explain these various morphologies?
How do stars form in galaxies?
What controls the “galactic gas recycling” process?
6. Because galaxies are diffuse and often very faint objects, a site
with limited background noise provides a crucial advantage.
Because galaxies emit light across a broad range of wavelengths,
accessing a large section of the EM spectrum is necessary.
visible
Near-IR
Because galaxies can contain highly variable phenomena (e.g.
supermassive black holes), temporal monitoring is important.
E.g. Most of the energy emitted by star
forming galaxies is not in the visible light!
Extragalactic Studies: Site Requirements
Toth et al. , 2013
8. Where can we find:
• A site with very low background noise
• A site with access to multiple wavelengths
• A stable site allowing very long (or frequent)
and accurate photometric observations
Best Options
OPTION 1 OPTION 2 OPTION 3
High Mountains Deep Space Moon’s Surface
E.g. JWSTE.g. Maunakea
14. Large Magellanic Cloud (LMC)
Star Forming
Region
Star Forming
Region
Bar (older stars)
In theory, massive star forming regions = strong ultraviolet emitters
16. Despite difficult conditions and somewhat limited
technology compared to current days, Apollo 16
proved that astronomy from the Moon, including
observations one nearby galaxy, was possible.
So:
What’s Next ?
19. Lunar Ultraviolet Telescope (LUT)
Wang et al. (2015)
Main Science goals
• Variable/Cataclysmic Stars
• AGN variability
• Galaxy mapping
The LUT is operated
during the lunar
daytime
The LUT is the first robotic
telescope working from
another world
20. Wang et al. (2015)
Telescope
throughput:
Blue, hot stars
T=12,000°
T=10,000°
T=8,000°
21. ILOA and Chang’e 3
CFHT UH Hilo
“Let’s try to observe
a large, nearby galaxy!”
22. Galaxy Candidates?
• Must be as large and bright as possible
• Must include numerous star forming regions (blue, massive stars)
• Must be visible from the LUT, when Sun is very low on the horizon
M31
M33
M101
M106
Images by GALEX
23. M101 is visible with LUT during two narrow windows
of opportunity when the Sun is low on the horizon!
LUT Simulator
In August 2014, 10 hours are allocated by the
Chang’e 3 Team to attempt these observations!
26. The Reason: Severe scattered light from the Sun
For this first tentative, the Sun
was higher than planned due to
technical delays. Observing diffuse
objects during daytime is hard,
even from the Moon!
4000 counts
32. Extragalactic Astronomy From the Moon:
M101 imaging by the LUT is a small step
but progress nonetheless!
The lunar surface is a real potential site to
conduct research programs on galaxies that
could be difficult to conduct elsewhere
[ Is it cost effective? I don’t know! But deep space
observatories are not cheap either ... ]
33. Extragalactic Astronomy from the Moon: Thoughts
• Small-size telescope: darker conditions and monitoring ?
• Robotic medium-size (1 meter) telescope?
• Very Large (>20m?) Liquid Mirror Telescope for deep sky
imaging (cosmology)?
Klimas et al. (2011)
