A Possible Bias Model for Quasars

Abstract

We propose that the majority of quasars at redshift $z\sim 1-5$ formed in the environment of new born collapsed halos with 1-D velocity dispersion $σ_v^{1d} \sim 400 \kms$. The harboring coefficient $f$ of quasars per halo and the lifetime of quasars depend only on local process, not modulated by the density inhomogeneities on scales larger than the size of the halos. Thus, the bias of quasars on scale larger than the size of these halos is mainly determined by the parameter ${\sigma }_v$ used for quasar environment identification. With this model, the popular structure formation models, like SCDM and LCDM, can be fairly well reconciled with the data of quasars, including a. observed feature of the environment for quasars; b. redshift evolution of quasar abundance; c. the two-point correlation functions of quasars. This bias model predicts that the correlation function of quasars doesn't significantly evolve, or only slightly increases with redshift.

accepted for publication in ApJ Letters; 11 pages with 3 figures included

References in corpus (1)

• Quasar clustering: evidence for an increase with redshift and implications for the nature of AGNs

Cited by in corpus (8)

• The abundance and clustering of dark haloes in the standard Lambda CDM cosmogony
• Accurate fitting formula for the two-point correlation function of the dark matter halos
• Two-point correlation function of high-redshift objects: an explicit formulation on a light-cone hypersurface
• QSOs and Absorption Line Systems Surrounding the Hubble Deep Field
• Can Geometric Test Probe the Cosmic Equation of State ?
• Small-Scale Fluctuations in Cosmic X-ray Background : A Power Spectrum Approach
• The Reionization History in the Lognormal Model
• Cosmological Constraints on the Host Halos of GRBs