TY - JOUR
T1 - Quasar clustering from SDSS DR5
T2 - Dependences on physical properties
AU - Shen, Yue
AU - Strauss, Michael A.
AU - Ross, Nicholas P.
AU - Hall, Patrick B.
AU - Lin, Yen Ting
AU - Richards, Gordon T.
AU - Schneider, Donald P.
AU - Weinberg, David H.
AU - Connolly, Andrew J.
AU - Fan, Xiaohui
AU - Hennawi, Joseph F.
AU - Shankar, Francesco
AU - Vanden Berk, Daniel E.
AU - Bahcall, Neta A.
AU - Brunner, Robert J.
PY - 2009
Y1 - 2009
N2 - Using a homogenous sample of 38,208 quasars with a sky coverage of 4000 deg2 drawn from the Sloan Digital Sky Survey Data Release Five quasar catalog, we study the dependence of quasar clustering on luminosity, virial black hole (BH) mass, quasar color, and radio loudness. At z < 2.5, quasar clustering depends weakly on luminosity and virial BH mass, with typical uncertainty levels 10% for the measured correlation lengths. These weak dependences are consistent with models in which substantial scatter between quasar luminosity, virial BH mass, and the host dark matter halo mass has diluted any clustering difference, where halo mass is assumed to be the relevant quantity that best correlates with clustering strength. However, the most luminous and most massive quasars are more strongly clustered (at the 2σ level) than the remainder of the sample, which we attribute to the rapid increase of the bias factor at the high-mass end of host halos. We do not observe a strong dependence of clustering strength on quasar colors within our sample. On the other hand, radio-loud quasars are more strongly clustered than are radio-quiet quasars matched in redshift and optical luminosity (or virial BH mass), consistent with local observations of radio galaxies and radio-loud type 2 active galactic nuclei. Thus, radio-loud quasars reside in more massive and denser environments in the biased halo clustering picture. Using the Sheth etal. (2001) formula for the linear halo bias, the estimated host halo mass for radio-loud quasars is 1013 h -1 M ⊙, compared to 2 × 1012 h -1 M ⊙ for radio-quiet quasar hosts at z 1.5.
AB - Using a homogenous sample of 38,208 quasars with a sky coverage of 4000 deg2 drawn from the Sloan Digital Sky Survey Data Release Five quasar catalog, we study the dependence of quasar clustering on luminosity, virial black hole (BH) mass, quasar color, and radio loudness. At z < 2.5, quasar clustering depends weakly on luminosity and virial BH mass, with typical uncertainty levels 10% for the measured correlation lengths. These weak dependences are consistent with models in which substantial scatter between quasar luminosity, virial BH mass, and the host dark matter halo mass has diluted any clustering difference, where halo mass is assumed to be the relevant quantity that best correlates with clustering strength. However, the most luminous and most massive quasars are more strongly clustered (at the 2σ level) than the remainder of the sample, which we attribute to the rapid increase of the bias factor at the high-mass end of host halos. We do not observe a strong dependence of clustering strength on quasar colors within our sample. On the other hand, radio-loud quasars are more strongly clustered than are radio-quiet quasars matched in redshift and optical luminosity (or virial BH mass), consistent with local observations of radio galaxies and radio-loud type 2 active galactic nuclei. Thus, radio-loud quasars reside in more massive and denser environments in the biased halo clustering picture. Using the Sheth etal. (2001) formula for the linear halo bias, the estimated host halo mass for radio-loud quasars is 1013 h -1 M ⊙, compared to 2 × 1012 h -1 M ⊙ for radio-quiet quasar hosts at z 1.5.
KW - Black hole physics
KW - Cosmology: observations
KW - Galaxies: active
KW - Large-scale structure of universe
KW - Quasars: general
KW - Surveys
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U2 - 10.1088/0004-637X/697/2/1656
DO - 10.1088/0004-637X/697/2/1656
M3 - Article
AN - SCOPUS:66649086269
SN - 0004-637X
VL - 697
SP - 1656
EP - 1673
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
ER -