First Measurement of the Clustering Evolution of Photometrically-Classified Quasars

dc.creatorMyers, Adam D.
dc.creatorBrunner, Robert J.
dc.creatorRichards, Gordon T.
dc.creatorNichol, Robert C.
dc.creatorSchneider, Donald P.
dc.creatorBerk, Daniel E. Vanden
dc.creatorScranton, Ryan
dc.creatorGray, Alexander G.
dc.creatorBrinkmann, Jon
dc.date2005-10-12
dc.date2005-10-24
dc.date.accessioned2026-07-07T06:43:51Z
dc.date.available2026-07-07T06:43:51Z
dc.descriptionWe present new measurements of the quasar autocorrelation from a sample of \~80,000 photometrically-classified quasars taken from SDSS DR1. We find a best-fit model of $ω(θ) = (0.066\pm^{0.026}_{0.024})θ^{-(0.98\pm0.15)}$ for the angular autocorrelation, consistent with estimates from spectroscopic quasar surveys. We show that only models with little or no evolution in the clustering of quasars in comoving coordinates since z~1.4 can recover a scale-length consistent with local galaxies and Active Galactic Nuclei (AGNs). A model with little evolution of quasar clustering in comoving coordinates is best explained in the current cosmological paradigm by rapid evolution in quasar bias. We show that quasar biasing must have changed from b_Q~3 at a (photometric) redshift of z=2.2 to b_Q~1.2-1.3 by z=0.75. Such a rapid increase with redshift in biasing implies that quasars at z~2 cannot be the progenitors of modern L* objects, rather they must now reside in dense environments, such as clusters. Similarly, the duration of the UVX quasar phase must be short enough to explain why local UVX quasars reside in essentially unbiased structures. Our estimates of b_Q are in good agreement with recent spectroscopic results, which demonstrate the implied evolution in b_Q is consistent with quasars inhabiting halos of similar mass at every redshift. Treating quasar clustering as a function of both redshift and luminosity, we find no evidence for luminosity dependence in quasar clustering, and that redshift evolution thus affects quasar clustering more than changes in quasars' luminosity. We provide a new method for quantifying stellar contamination in photometrically-classified quasar catalogs via the correlation function.
dc.description34 pages, 10 figures, 1 table, Accepted to ApJ after: (i) Minor textual changes; (ii) extra points added to Fig. 5
dc.identifierhttps://arxiv.org/abs/astro-ph/0510371
dc.identifierhttp://arxiv.org/abs/astro-ph/0510371
dc.identifierAstrophys.J. 638 (2006) 622-634
dc.identifierdoi:10.1086/499093
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/102571
dc.subjectAstrophysics
dc.titleFirst Measurement of the Clustering Evolution of Photometrically-Classified Quasars
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