Star Formation in Distant Red Galaxies: Spitzer observations in the Hubble Deep Field South
Abstract
We present Spitzer 24micron imaging of 1.5 < z < 2.5 Distant Red Galaxies (DRGs) in the 10arcmin by 10arcmin Extended Hubble Deep Field South of the Multiwavelength Survey by Yale-Chile. We detect 65% of the DRGs with K_AB < 23.2 mag at S_24micron > 40uJy, and conclude that the bulk of the DRG population are dusty active galaxies. A mid-infrared (MIR) color analysis with IRAC data suggests that the MIR fluxes are not dominated by buried AGN, and we interpret the high detection rate as evidence for a high average star formation rate of <SFR> = 130+/-30 M/yr. From this, we infer that DRGs are important contributors to the cosmic star formation rate density at z ~ 2, at a level of \~0.02 M/yr/Mpc^3 to our completeness limit of K_AB = 22.9 mag
Keywords
Cite
@article{arxiv.astro-ph/0511598,
title = {Star Formation in Distant Red Galaxies: Spitzer observations in the Hubble Deep Field South},
author = {Tracy Webb and Pieter van Dokkum and Eiichi Egami and Giovanni Fazio and Marijn Franx and Eric Gawiser and David Herrera and Jiasheng Huang and Ivo Labbe and Paulina Lira and Danilo Marchesini and Jose Maza and Ryan Quadri and Gregory Rudnick and Paul van der Werf},
journal= {arXiv preprint arXiv:astro-ph/0511598},
year = {2009}
}
Comments
4 pages, 3 figures, accepted for publication in ApJL