Galaxies 09: Assembly, Gas Content and Star Formation History of Galaxies
Mark Lacy
NRAO/NAASC
Dust obscured radio-quiet quasars at high redshifts
The currently popular paradigm of massive galaxy and black hole co-evolution, in which galaxy mergers trigger both starbursts and quasar activity at high redshifts, predicts a large fraction of dust obscured quasars at $z\stackrel{>}{_{\sim}}2$. Candidates for such objects can be found relatively easily using mid-infrared selection from Spitzer surveys, but obtaining redshifts (and hence space densities, luminosities and other physical parameters) is much more challenging, given the faintness of these objects in the optical and near-infrared. We will present our progress to date towards obtaining a large sample of dust obscured, radio-quiet high redshift quasars, preliminary results from which indicate that dust obscured objects are likely to dominate the co-moving space density of luminous quasars at $z\stackrel{>}{_{\sim}}2.5$. We will also present early follow-up work in the far-infrared and submm which suggests that many of these objects are indeed associated with highly luminous starbursts, and discuss how ALMA and EVLA can be used to help us understand the nature of these objects and their relation to the normal quasar population.
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