DIRECT EVIDENCE FOR TERMINATION OF OBSCURED STAR FORMATION BY RADIATIVELY DRIVEN OUTFLOWS IN REDDENED QSOs

Abstract

We present optical to far-infrared photometry of 31 reddened QSOs that show\nevidence for radiatively driven outflows originating from AGN in their\nrest-frame UV spectra. We use these data to study the relationships between the\nAGN-driven outflows, and the AGN and starburst infrared luminosities. We find\nthat FeLoBAL QSOs are invariably IR-luminous, with IR luminosities exceeding\n10^{12} Solar luminosities in all cases. The AGN supplies 76% of the total IR\nemission, on average, but with a range from 20% to 100%. We find no evidence\nthat the absolute luminosity of obscured star formation is affected by the\nAGN-driven outflows. Conversely, we find an anticorrelation between the\nstrength of AGN-driven outflows, as measured from the range of outflow\nvelocities over which absorption exceeds a minimal threshold, and the\ncontribution from star formation to the total IR luminosity, with a much higher\nchance of seeing a starburst contribution in excess of 25% in systems with weak\noutflows than in systems with strong outflows. Moreover, we find no convincing\nevidence that this effect is driven by the IR luminosity of the AGN. We\nconclude that radiatively driven outflows from AGN can have a dramatic,\nnegative impact on luminous star formation in their host galaxies. We find that\nsuch outflows act to curtail star formation such that star formation\ncontributes less than ~25% of the total IR luminosity. We also propose that the\ndegree to which termination of star formation takes place is not deducible from\nthe IR luminosity of the AGN.\n