1. The Science Case
Hubble Space
Telescope
CELT+AO
HDF

2. CELT Science Opportunities
New discovery space.
Lesson from Keck is that it is difficult to anticipate the most exciting science areas a decade in advance. Major advances in capability have always resulted in unexpected new discoveries.
Anticipated Science Areas:
The development and evolution of structure in the universe
The emergence of the first galaxies
The physics of star formation
The formation and evolution of planetary systems
Physical processes in the Solar System
The star formation and chemical evolution history of galaxies in the local universe.
Note that an extensive science-with-30m-telescopes case has been developed as part of the decade survey, our project, GSMT

3. CELT Science Opportunities
9x the light gathering capability of a Keck Telescope
12.5x the spatial resolution of the Hubble Space Telescope with AO
Sensitivity scales between D2 and D4 (factor of 80 improvement!) for different regimes of use (seeing-limited vs diffraction-limited) and source morphology
CELT will be the first facility designed to take advantage of AO and the D4 gain.
Note that an extensive science-with-30m-telescopes case has been developed as part of the decade survey, our project, GSMT

4. Baryonic Structure at High Redshift
The 3-D Structure of the diffuse IGM can be probed using “tomography” via multiple sightlines through the survey volume
With CELT, the surface density of background sources will be 2 orders of magnitude higher.
Trace the development of structure and the chemical enrichment history of the Universe in the early epochs
Mapping kinematics of gas translates directly in to tracing mass

5. The Birth and Evolution of Galaxies
With 8-10m telescopes we are glimpsing the tip of the iceberg with the first galaxies identified beyond z=1
Understanding the details of the formation and assembly epoch for galaxies will be a major area in astronomy and astrophysics for the next few decades. The light grasp and spatial resolution of a 30m telescope is essential
Spatially dissecting galaxies allows access to physical parameters: mass, chemistry, kinematics (near-IR accesses rest-frame optical for much of the “epoch of galaxy formation”)

6. Diffraction-limited Observations
The diffraction limit of a 30m telescope opens up tremendous possibilities
1 AU at 150 parsecs (the nearest star forming regions)
50 parsecs at z = 2-8 means that distant galaxies are resolved in great detail.
Star formation, planet formation, galaxy assembly, solar system studies, spectoscopy of faint sources
near-IR mid-IR

7. Resolved Stellar Populations to Virgo
With CELT, studies of the star-formation and chemical evolution of nearby galaxies will be possible throughout the Local Universe.
Currently limited to the Milky Way Galaxy and its dwarf galaxy complement.
CELT
NGST

8. Why 30m?
A 30m telescope will remain competitive for decades (because of its cost, it is likely that only ESO can eventually compete, and we have at least 5 yrs head start).
The telescope is the platform on which AO and instrumentation can be advanced with improvements in technology. It is hard to increase the telescope aperture after the telescope is built!
Due to design improvements and the Keck experience, CELT is feasible and affordable.
The Keck Telescopes allowed UC/Caltech to lead many areas of astronomical research for the past decade. Our goal is to remain at the forefront of astrophysics research.