NOAO >   Observing Info >   Approved Programs >   2009B-0191

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Proposal Information for 2009B-0191


PI: Xin Liu, Princeton University, xinliu@astro.princeton.edu
Address: Peyton Hall Ivy Lane, Princeton, NJ 08544, USA

CoI: Nadia Zakamska, IAS
CoI: Jenny Greene, Princeton University
CoI: Michael Strauss, Princeton University

Title: Stellar Populations in the Host Galaxies of Luminous Obscured Quasars

Abstract: Supermassive black holes in the centers of galaxies are thought to predominantly grow in brief Eddington-rate quasar phases accompanied by starbursts, but on-going starbursts in luminous quasars are difficult to observe. We propose to conduct deep optical spectroscopy of a sample of 21 luminous obscured quasars at z 0.5 to study stellar populations in their host galaxies. Our targets have intrinsic luminosities of M_V < -26 mag, a regime at which quasars accrete at close to Eddington rates, but for which direct high S/N host galaxy spectroscopy is virtually inaccessible for unobscured quasars. In our pilot sample studied using GMOS, 30% of our objects contained substantial infant stellar populations; here we specifically target candidates exhibiting tentative Wolf-Rayet features in their SDSS spectra, which however have poor S/N in the continuum. We will determine the presence of infant starbursts ( 5 Myr) by measuring the telltale Wolf-Rayet features around He II 4686, and by population modeling of the stellar continuum. With high S/N GMOS spectra of a statistically large sample of objects, we will measure stellar velocity dispersions to infer black hole masses and accretion rates, analyze stellar populations, investigate the luminosity dependence of star formation activity, and achieve the first statistical quantification of infant starbursts in luminous quasars.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



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