The Long Faint Tail of the High-Redshift Galaxy Population
Abstract
We study the properties of very faint, sub-L* Lyman break galaxies at z~2-5 - thus far a largely neglected but numerically and energetically very important population. We find that the LBG luminosity function undergoes luminosity-dependent evolution: the number of luminous galaxies remains constant while the number of faint ones grows with time. The total UV luminosity density increases with cosmic time from at least z~5 until reaching a peak or a plateau around z~2 - behaviour that is governed by the sub-L* galaxies in the LF's "faint tail". Using broadband SED fitting we find a nearly-linear relationship between SFR and galaxy stellar mass at z~2. A typical L* LBG at z~2 shows a stellar mass of ~10^10M_sun, remarkably similar to the bimodality mass at low redshift. This similarity suggests that the mechanisms responsible for the galaxy bimodality at low-z may have also been at play at z~2.
Keywords
Cite
@article{arxiv.astro-ph/0612117,
title = {The Long Faint Tail of the High-Redshift Galaxy Population},
author = {Marcin Sawicki and Ikuru Iwata and Kouji Ohta and David Thompson and Naoyuki Tamura and Masayuki Akiyama and Kentaro Aoki and Masataka Ando and Gaku Kiuchi},
journal= {arXiv preprint arXiv:astro-ph/0612117},
year = {2007}
}
Comments
To appear in the proceedings of 'At the Edge of the Universe', October 2006, Sintra, Portugal