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Astrophysical Journal (2011)
  • S. L. Cales, University of Wyoming
  • M. S. Brotherton, University of Wyoming
  • Zhaohui Shang, Tianjin Normal University
  • Vardha Nicola Bennert, University of California - Santa Barbara
  • Gabriela Canalizo, University of California - Riverside
  • R. Stoll, Ohio State University - Main Campus
  • R. Ganguly, University of Michigan-Flint
  • D. Vanden Berk, Saint Vincent College
  • Cassandra Paul, San Jose State University
  • A. Diamond-Stanic, University of California - San Diego
We present images of 29 post-starburst quasars (PSQs) from a Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) Wide Field Channel Snapshot program. These broadlined active galactic nuclei (AGNs) possess the spectral signatures of massive (Mburst ∼ 1010 M), moderate-aged stellar populations (hundreds of Myr). Thus, their composite nature provides insight into the AGN–starburst connection. We measure quasar-to-host galaxy light contributions via semi-automated two-dimensional light profile fits of point-spread-function-subtracted images. We examine the host morphologies and model the separate bulge and disk components. The HST/ACS-F606W images reveal an equal number of spiral (13/29) and early-type (13/29) hosts, with the remaining three hosts having indeterminate classifications. AGNs hosted by early-type galaxies have on average greater luminosity than those hosted by spiral galaxies. Disturbances such as tidal tails, shells, star-forming knots, and asymmetries are seen as signposts of interaction/merger activity. Disturbances like these were found in 17 of the 29 objects and are evenly distributed among early-type and spiral galaxies. Two of these systems are clearly merging with their companions. Compared to other AGNs of similar luminosity and redshift, these PSQs have a higher fraction of early-type hosts and disturbances. Our most luminous objects with disturbed early-type host galaxies appear to be consistent with merger products. Thus, these luminous galaxies may represent a phase in an evolutionary scenario for merger-driven activity. Our less luminous objects appear to be consistent with Seyfert galaxies not requiring triggering by major mergers. Many of these Seyferts are barred spiral galaxies.
  • galaxies: active,
  • galaxies: evolution,
  • galaxies: interactions,
  • quasars: general
Publication Date
October 24, 2011
Publisher Statement
This article was originally published in The Astrophysical Journal, volume 741, issue 2. © 2011. The American Astronomical Society. All rights reserved.

This article is also available online at the following link:
Citation Information
S. L. Cales, M. S. Brotherton, Zhaohui Shang, Vardha Nicola Bennert, et al.. "HUBBLE SPACE TELESCOPE IMAGING OF POST-STARBURST QUASARS" Astrophysical Journal Vol. 741 Iss. 2 (2011) ISSN: 0004-637X
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