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Title: SPITZER OBSERVATIONS OF YOUNG RED QUASARS

Journal Article · · Astrophysical Journal
 [1];  [2];  [3];  [4];  [5];  [6]
  1. Leibniz Institut fuer Astrophysik Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany)
  2. NRAO, 520 Edgemont Road, Charlottesville, VA 22903 (United States)
  3. Department of Astronomy, Cornell University, 219 Space Sciences Building, Ithaca, NY 14853 (United States)
  4. Department of Physics, Yale University, P.O. Box 208120, New Haven, CT 06520 (United States)
  5. Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States)
  6. Infrared Processing and Analysis Center, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States)

We present mid-infrared spectra and photometry of 13 redshift 0.4 < z < 1 dust reddened quasars obtained with Spitzer IRS and MIPS. We compare properties derived from their infrared spectral energy distributions (intrinsic active galactic nucleus (AGN) luminosity and far-infrared luminosity from star formation) to the host luminosities and morphologies from Hubble Space Telescope imaging, and black hole masses estimated from optical and/or near-infrared spectroscopy. Our results are broadly consistent with models in which most dust reddened quasars are an intermediate phase between a merger-driven starburst triggering a completely obscured AGN, and a normal, unreddened quasar. We find that many of our objects have high accretion rates, close to the Eddington limit. These objects tend to fall below the black hole mass-bulge luminosity relation as defined by local galaxies, whereas most of our low accretion rate objects are slightly above the local relation, as typical for normal quasars at these redshifts. Our observations are therefore most readily interpreted in a scenario in which galaxy stellar mass growth occurs first by about a factor of three in each merger/starburst event, followed sometime later by black hole growth by a similar amount. We do not, however, see any direct evidence for quasar feedback affecting star formation in our objects, for example, in the form of a relationship between accretion rate and star formation. Five of our objects, however, do show evidence for outflows in the [O III]5007 A emission line profile, suggesting that the quasar activity is driving thermal winds in at least some members of our sample.

OSTI ID:
22092198
Journal Information:
Astrophysical Journal, Vol. 757, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English