Evolution of the 3.6 micron Cluster Luminosity Function
摘要
We have measured the 3.6 micron cluster luminosity function (LF) using a sample of 123 galaxy clusters selected from the 4 degree^2 Spitzer First Look Survey (FLS). The clusters were selected on the basis of their R - 3.6 micron colors using the cluster red-sequence technique of Gladders & Yee (2000). The binned LFs are well-fit by a Schechter function at all redshifts. However, we note two interesting trends. Firstly, the evolution of Mstar with redshift is consistent with models that form galaxies in a single-burst of star-formation at z > 2.0, and evolve passively thereafter. Secondly, the faint-end slope of the LF appears to become shallower at higher redshift. We conclude that the most massive galaxies were formed in the cluster at high redshift (z > 2), while lower-mass galaxies have subsequently been accreted from the field at lower redshift (z ~ 0.5). These results are consistent with the ``downsizing'' picture seen in previous cluster studies using smaller samples.
关键词
引用
@article{arxiv.astro-ph/0503640,
title = {Evolution of the 3.6 micron Cluster Luminosity Function},
author = {Adam Muzzin and Gillian Wilson and Mark Lacy},
journal= {arXiv preprint arXiv:astro-ph/0503640},
year = {2007}
}
备注
To appear in the conference proceedings "Spitzer Space Telescope: New Views of the Universe, held Nov. 2004 in Pasadena, 2 pages including 1 figure