NOAO >   Observing Info >   Approved Programs >   2012B-0181

Small NOAO Logo

Proposal Information for 2012B-0181


PI: Nadia L. Zakamska, Johns Hopkins University, zakamska@pha.jhu.edu
Address: Dpt of Physics and Astronomy, Bloomberg Ctr 366, 3400 N Charles St, Baltimore, MD 21210, USA

CoI: Rachael Alexandroff, Princeton University
CoI: Michael A. Strauss, Princeton University
CoI: Paul Smith, University of Arizona
CoI: Jenny E. Greene, Princeton University

Title: Spectropolarimetry of high-redshift type 2 quasar candidates

Abstract: Type 2 quasars are luminous active galactic nuclei whose central engines and broad-line regions are obscured by intervening material. The prevalence and demographics of these objects at the peak of quasar and star formation epoch (z\ga 2) remain controversial because these objects are faint at optical wavelengths and are therefore hard to find. Using the data from the on-going SDSS-III survey, we discovered over a hundred type 2 quasar candidates at z=2-4. These objects have strong narrow emission lines and faint continuum in their rest-frame UV spectra, as well as mid-IR luminosities (as measured by WISE) which reach a few \times 10^46 erg/sec. We request 20 hours of MMT time to perform spectropolarimetry of 10 candidate objects as part of our comprehensive multi-wavelength study of type 2 quasars. These observations will probe the hidden central engine and the broad-line region in scattered light. The measurement of polarization will allow us to immediately test our hypothesis that these objects are obscured quasars, with their faint continuum dominated by scattered light emission. Similar observations with MMT in 2004 by our group resulted in an unambiguous confirmation of our z<1 candidates as obscured quasars, allowing us to extend the unification model of active nuclei to high luminosities and to determine the prevalence of obscured quasars in the local universe.


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



NOAO >   Observing Info >   Approved Programs >   2012B-0181

noaoprop-help@noao.edu

Small NOAO Logo