AAS 203rd Meeting, January 2004
Session 78 Quasars and QSOs
Poster, Wednesday, January 7, 2004, 9:20am-6:30pm, Grand Hall

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[78.03] Are Quasars associated with Dark Matter Overdensities?

D.J. Norman (CTIO/NSF AAPF), D. Loomba (Univ. of New Mexico), DLS Team

Hierarchical models of galaxy evolution have been successful in explaining the observed properties of galaxies and clusters over a large range in redshift. Recently, Kauffmann and Haehnelt (2002) have also incorporated the formation and evolution of quasars in these models. Although there may also be other triggers of quasar activity in some galaxies, e.g. Seyferts, the overall agreement of these models with properties of the quasar population suggests that quasar formation through hierarchical growth of large scale structures is important in explaining the formation of a majority of quasars. Turning the argument around implies that most quasars are luminous markers of merging (or merged) massive dark halos.

Members of the Deep Lens Survey (DLS) team have discovered dark matter overdensities through shear mapping of background galaxies (Wittman et al. 2003). Here we present near-IR data, methods and preliminary results of a search for quasar candidates associated with one of these matter overdensities. A wider search for associations of dark matter mass overdensities and quasars will allow us to test the validity of assumptions made in models in which quasars are formed as a result of hierarchical structure formation.

This work is supported, in part, through funding from the NSF Astronomy and Astrophysics Postdoctoral fellowship.


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© 2003. The American Astronomical Soceity.