CfA OIR Division Lunch Talks
Wednesday, September 19, 2012, 11:00 am, Pratt Conference Room

Connecting AGN Accretion and Obscuration to Host Galaxy Evolution

Jon Trump (UCSC)

I will present a co-evolutionary picture linking AGNs and their host galaxies, using observations from the SDSS, COSMOS, and CANDELS surveys to constrain different theoretical models of AGN/galaxy growth. In particular AGNs can be unified by their accretion rate and obscuration, and each unification parameter correlates to various host galaxy properties. Rapidly accreting AGNs tend to lie in disturbed galaxies with merger signatures (when obscured), or bulge-dominated galaxies with recent starbursts (when unobscured). In contrast weakly accreting AGNs are primarily found in undisturbed disks. New IR spectroscopy in CANDELS suggests that at z~2, secular fueling of low-level AGNs is common even to low stellar masses (M*~10^9 M_sun). Meanwhile mergers or violent disk instabilities are necessary only to explain the most powerful AGNs. I will conclude by synthesizing the varied observations into a toy "unified model" for AGN/galaxy coevolution, linking black hole accretion to the rise and quenching of galaxy star formation.