Clustering Analyses of 300,000 Photometrically Classified Quasars. I. Luminosity and Redshift Evolution in Quasar Bias

Abstract

Using $300,000 photometrically classified quasars, by far the largest quasar sample ever used for such analyses, we study the redshift and luminosity evolution of quasar clustering on scales of $50 h À1 kpc to $20 h À1 Mpc from redshifts ofz $ 0:75Y2:28. We parameterize our clustering amplitudes using realistic dark matter models and find that a ÃCDM power spectrum provides a superb fit to our data with a redshift-averaged quasar bias of b¯z ¼1:40 Q ¼ 2:41 AE 0:08 (P < 2 ¼ 0:847) for 8 ¼ 0:9. This represents a better fit than the best-fit power-law model [! ¼ 0:0493 AE ð 0:0064Þ À0:928AE0:055 ; P < 2 ¼ 0:482]. We find b Q increases with redshift. This evolution is significant at >99.6% using our data set alone, increasing to >99.9999% if stellar contamination is not explicitly parameterized. We measure the quasar classification efficiency across our full sample as a ¼ 95:6 AE 4:4 1:9 %, a star-quasar separation comparable to the star-galaxy separation in many photometric studies of galaxy clustering. We derive the mean mass of the dark matter halos hosting quasars as M DMH ¼ (5:2 AE 0:6) ; 10 12 h À1 M . Atz $ 1:9 we find a 1.5 deviation from luminosityindependent quasar clustering; this suggests that increasing our sample size by a factor of $1.8 could begin to constrain any luminosity dependence in quasar bias at z $ 2. Our results agree with recent studies of quasar environments at z < 0:4, which detected little luminosity dependence to quasar clustering on proper scales k50 h À1 kpc. At z < 1:6, our analysis suggests that b Q is constant with luminosity to within Áb Q $ 0:6, and that, for g < 21, angular quasar autocorrelation measurements are unlikely to have sufficient statistical power at z P 1:6 to detect any luminosity dependence in quasars' clustering. Subject headingg s: cosmology: observations -large-scale structure of universe -quasars: general -surveys

Clustering of intermediate redshift quasars using the final SDSS III-BOSS sample

“…where the L subscript refers to the neglected pixel and the random pair ratio, RRL/RR, compensates for the relative area through the relative random catalog size in each pixel (e.g Myers et al 2007a). …”

“…Alternatively, this relationship could occur because both supermassive black holes and their host galaxies are governed by the properties of their parent dark matter halo (e.g., Ferrarese 2002). Quasar populations show a high level of clustering, and it is inferred that they occupy dark matter halos of ∼ 10 12 h −1 M⊙ at most epochs (e.g., Porciani, Magliocchetti & Norberg 2004;Croom et al 2005;Myers et al 2006Myers et al , 2007aShen et al 2007 The geometry of the cosmological world model is now known with remarkable precision, and even systematic differences are at the few percent level (e.g., Hinshaw et al 2013;Planck Collaboration et al 2014;Anderson et al 2014;Aubourg et al 2014). The spectrum of primordial fluctuations and its evolution over cosmic history is also becoming increasingly well constrained.…”

“…In addition to direct measurements of the relationship between the luminosity of Active Galactic Nuclei (henceforth AGN) luminosity and star formation in galaxies (e.g., Alexander & Hickox 2012;Mullaney et al 2012;Ross et al 2012b), great progress has been driven by two statistical measures of the quasar population: the luminosity function and clustering. The quasar luminosity function is increasingly well-understood (e.g., see Ross et al 2013a, for a recent study) and there are now a large number of quasar clustering measurements in the optical at z < 2.2 across a range of scales (e.g., Porciani, Magliocchetti & Norberg 2004;Croom et al 2005;Porciani & Norberg 2006;Hennawi et al 2006;Myers et al 2007aMyers et al ,b, 2008Ross et al 2009). Together, these measurements provide an increasingly coherent characterization of the dark matter environments inhabited by quasars and what fraction of quasars ignite in those environments (i.e., the quasar duty cycle; Cole & Kaiser 1989;Haiman & Hui 2001;Martini & Weinberg 2001;White, Martini & Cohn 2008;.…”

Clustering on very small scales from a large sample of confirmed quasar pairs: does quasar clustering track from Mpc to kpc scales?

“…An appropriate random catalogue will mimic the angular and redshift distribution of the data, in the absence of any clustering. Since our KDE-complete sample of binary quasars is drawn from the KDE catalogue described in §2, the random catalogue needs to have the same overall angular and redshift coverage as the KDE catalogue (see, e.g., Myers et al 2006Myers et al , 2007a. The entire volume of the KDE catalogue comprises ∼ 41.93 (h −1 Gpc ) 3 .…”

A unifying evolutionary framework for infrared-selected obscured and unobscured quasar host haloes

“…Lacy et al 2004;Treister et al 2004;Stern et al 2005;Hickox et al 2007Hickox et al , 2009Hickox et al , 2011Stern et al 2012;Hainline et al 2014;DiPompeo et al 2014b;Hickox et al 2014;Lacy et al 2015;DiPompeo et al 2015; that has historically been dominated by optically detected unobscured systems (e.g. Croom et al 2004Croom et al , 2005Richards et al 2006a,b;Myers et al 2007;Croom et al 2009;Ross et al 2009;Shen et al 2009;Bonoli et al 2009;Eftekharzadeh et al 2015). This has resulted in tension between the prevailing paradigms that attempt to explain the physical origin of observational quasar subclasses.…”