HerMES: The far-infrared emission from dust-obscured galaxies

Abstract

The far-infrared (far-IR) luminosities of luminous infrared galaxies (LIRGs) and ultra-LIRGs (ULIRGs) are dominated by reprocessed thermal dust emission, due to a combination of star formation and active galactic nucleus (AGN) activity, with star formation typically being the more dominant component (e.g., Watabe et al. 2009; Elbaz et al. 2010). Locally, these sources are rare, although out to z - 1 they become more numerous and increasingly dominate the IR luminosity function of galaxies with increasing redshift (e.g., Le Floc’h et al. 2005; P´erez-Gonz´alez et al. 2005; Caputi et al. 2007; Magnelli et al. 2009; Rodighiero et al. 2010; Eales et al. 2010). (U)LIRGs are thought to trace a phase of intense star formation activity, which is likely followed by, or partially concurrent with, an episode of vigorous black hole accretion. It is postulated that upon the cessation of these phases, each produces an early-type galaxy (Genzel et al. 2001; Farrah et al. 2003; Lonsdale et al. 2006; Veilleux et al. 2009).