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On the connection between metal absorbers and quasar nebulae

Chelouche, Doron and Ménard, Brice and Bowen, David V. and Gnat, Orly (2008) On the connection between metal absorbers and quasar nebulae. Astrophysical Journal, 683 (1). pp. 55-69. ISSN 0004-637X. doi:10.1086/588836.

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We establish a simple model for the distribution of cool (~10^4 K) gas around L* galaxies using the properties of strong Mg II absorption line systems as observational constraints. Our analysis suggests that the halos of L* galaxies are filled with cool gas clouds having sizes of order 1 kpc and densities of ~10^−2 cm^−3. We then investigate the physical conditions of a similar ensemble of clouds situated around a central quasar. We show that the flux from the quasar gives rise to (1) extended narrow line emission on ~100 kpc scales and (2) an anisotropy in the properties of the absorbing gas arising from the geometry of the quasar radiation field. Provided that quasars reside in gaseous halos more massive than those of L* galaxies, our predictions agree with the results from detections of both narrow emission line nebulae and ~100 kpc Mg II-absorbing halos around quasars, suggesting a common origin for these phenomena. We discuss the implications of our results for understanding quasar absorption line systems, quasar environments at high redshifts, and the quasar unification scheme.

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Additional Information:© 2008 The American Astronomical Society. Received 2007 March 1; accepted 2008 January 25. We thank Gary Ferland for creating and maintaining Cloudy as a publicly available code. We are grateful to Z. Zheng for invaluable help with the Lyα scattering calculations. We thank K. Jahnke, N. Murray, and D. York for commenting on an earlier version of this paper. We appreciate a thoughtful report by the referee. This research has been supported by NASA through a Chandra Postdoctoral Fellowship award PF4-50033. D. V. B. is funded through NASA Long Term Space Astrophysics grant NNG05GE26G.
Funding AgencyGrant Number
NASA Chandra Postdoctoral FellowshipPF4-50033
NASA Long Term Space AstrophysicsNNG05GE26G
Subject Keywords:atomic processes; galaxies: halos; quasars: absorption lines; quasars: emission lines
Issue or Number:1
Record Number:CaltechAUTHORS:20090407-132122094
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13876
Deposited By: Tony Diaz
Deposited On:16 Jul 2009 16:35
Last Modified:08 Nov 2021 22:41

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