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Title: MID-INFRARED SPECTRAL PROPERTIES OF POST-STARBURST QUASARS

We present Spitzer InfraRed Spectrograph low-resolution spectra of 16 spectroscopically selected post-starburst quasars (PSQs) at z {approx} 0.3. The optical spectra of these broad-lined active galactic nuclei (AGNs) simultaneously show spectral signatures of massive intermediate-aged stellar populations making them good candidates for studying the connections between AGNs and their hosts. The resulting spectra show relatively strong polycyclic aromatic hydrocarbon (PAH) emission features at 6.2 and 11.3 {mu}m and a very weak silicate feature, indicative of ongoing star formation and low dust obscuration levels for the AGNs. We find that the mid-infrared composite spectrum of PSQs has spectral properties between ULIRGs and QSOs, suggesting that PSQs are hybrid AGN and starburst systems as also seen in their optical spectra. We also find that PSQs in early-type host galaxies tend to have relatively strong AGN activities, while those in spiral hosts have stronger PAH emission, indicating more star formation.
Authors:
;  [1] ; ;  [2] ;  [3] ;  [4] ;  [5] ;  [6]
  1. Astrophysics Center, Tianjin Normal University, Tianjin 300387 (China)
  2. Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States)
  3. Departamento de Astronomia, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile)
  4. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
  5. Department of Computer Science, Engineering, and Physics, University of Michigan-Flint, Flint, MI 48502 (United States)
  6. Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States)
Publication Date:
OSTI Identifier:
22121885
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 772; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMIC DUST; COSMIC GAMMA BURSTS; EMISSION; GALAXIES; GALAXY NUCLEI; INFRARED SPECTRA; INFRARED SPECTROMETERS; POLYCYCLIC AROMATIC HYDROCARBONS; QUASARS; RESOLUTION; SILICATES; STARS