Discovery of an extremely red galaxy at z=0.65 with dusty star-formation and nuclear activity

In the course of the follow-up multiwavelength study of a deep radio survey we have discovered that the milli-Jansky radio source PDFJ011423 is a low-redshift (z = 0.65) extremely red galaxy (ERG) with K=15.3, R-K = 5.8 and J-K = 3.1. Optical, infrared and radio photometry, together with optical and near-infrared spectroscopy, reveal a heavily obscured galaxy (A_V=5-6, from the observed Balmer decrement) undergoing vigorous star formation and presenting an active galactic nucleus (AGN). PDFJ011423 is a representative member of the dusty ERG population, providing a local counterpart for studying more distant ERGs.