Star formation in QSO host galaxies
Abstract
Many of the conditions that are necessary for starbursts appear to be important in the triggering of QSOs. However, it is still debatable whether starbursts are ubiquitously present in galaxies harboring QSOs. In this paper we review our current knowledge from observations of the role of starbursts in different types of QSOs. Post-starburst stellar populations are potentially present in a majority of QSO hosts. QSOs with far-infrared colors similar to those of ultraluminous infrared galaxies invariably reside in merging galaxies that have interaction-induced starbursts of a few hundred Myr or less. Similar, but dramatically more luminous post-starburst populations are found in the recently discovered class of QSOs known as post-starburst QSOs, or Q + A's. Both of these classes, however, comprise only a small fraction (10–15%) of the total QSO population. The so-called ''red'' QSOs generally suffer from strong extinction at optical wavelengths, making them ideal candidates for the study of hosts. Their stellar populations typically show a post-starburst component as well, though with a larger range of ages. Finally, optical "classical" QSO hosts show traces of major star formation episodes (typically involving >10% of the mass of the stellar component) in the more distant past (1–2 Gyr). These starbursts appear to be linked to past merger events. It remains to be determined whether these mergers were also responsible for triggering the QSO activity that we observe today.
Additional Information
© 2006 Elsevier B.V. All rights reserved. Available online 27 July 2006. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs # GO-10421 and # SNAP-10588. We thank Nicola Bennert for her assistance in the reduction of Q + A spectra, and Zhaohui Shang and Rajib Ganguly for providing the original version of Fig. 2. This work was supported in part under proposal GO-10421 by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under contract NAS5- 26555. Additional support was provided by the National Science Foundation, under grant number AST 0507450. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.Additional details
- Eprint ID
- 22392
- DOI
- 10.1016/j.newar.2006.06.019
- Resolver ID
- CaltechAUTHORS:20110222-074508214
- GO-10421
- NASA
- NAS 5-26555
- NASA
- AST-0507450
- NSF
- Association of Universities for Research in Astronomy (AURA)
- Created
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2011-02-22Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field