EXTREME HOST GALAXY GROWTH IN POWERFUL EARLY-EPOCH RADIO GALAXIES

Abstract

During the first half of the universe's age, a heyday of star-formation must\nhave occurred because many massive galaxies are in place after that epoch in\ncosmic history. Our observations with the revolutionary Herschel Space\nObservatory reveal vigorous optically obscured star-formation in the\nultra-massive hosts of many powerful high-redshift 3C quasars and radio\ngalaxies. This symbiotic occurrence of star-formation and black hole driven\nactivity is in marked contrast to recent results dealing with Herschel\nobservations of X-ray selected active galaxies. Three archetypal radio\ngalaxies, at redshifts 1.132,1.575, and 2.474 are presented here, with inferred\nstar-formation rates of hundreds of solar masses per year. A series of\nspectacular coeval AGN/starburst events may have formed these ultra-massive\ngalaxies and their massive central black holes during their relatively short\nlifetimes.\n