The Space Density of Early Type Galaxies at 1 < z < 1.5 from the Las Campanas IR Survey
Abstract
We report the results of an optical and near-IR survey over 0.7 square degrees at high latitudes. The number-magnitude relation for galaxies with I - H > 3 is very steep, rising from a few per square degree at H = 17 to more than 1000 per square degree at H = 20.5. The surface density of red objects drops by roughly a factor of 10 for each magnitude of redder colors between 3 < I - H < 5. We use photometric redshifts to estimate the characteristic redshift for this sample, and its redshift extent, to be <z> = 1, σ (z) = 0.25. From this we deduce a space density of luminous red galaxies of 3 x 10-3 h-3 Mpc-3. This is somewhat less than that expected from passive evolution but roughly equal to the present day value. If these are massive early-type galaxies their space density exceeds the expectations based on hierarchical clustering models. This research was supported by the National Science Foundation under grant AST-9900806. The CIRSI camera was made possible by the generous support of the Raymond and Beverly Sackler Foundation.
- Publication:
-
American Astronomical Society Meeting Abstracts #198
- Pub Date:
- May 2001
- Bibcode:
- 2001AAS...198.7901M