Clustering of High-Redshift (z ≥ 2.9) Quasars from the Sloan Digital Sky Survey

By Yue Shen, M. Strauss, M. Oguri, J. Hennawi, Xiaohui Fan, Gordon Richards, P. Hall, James E. Gunn, D. Schneider, A. Szalay and 6 more. 2007

336 citations recorded by the source corpus.

We study the two-point correlation function of a uniformly selected sample of 4426 luminous optical quasars with redshift 2.9 ≤ z ≤ 5.4 selected over 4041 deg2 from the Fifth Data Release of the Sloan Digital Sky Survey. We fit a power-law to the projected correlation function wp(rp) to marginalize over redshift-space distortions and redshift errors. For a real-space correlation function of the form ξ(r) = (r/r0)-γ, the fitted parameters in comoving coordinates are r0 = 15.2 ± 2.7 h-1 Mpc and γ = 2.0 ± 0.3, over a scale range 4 h-1 Mpc ≤ rp ≤ 150 h-1 Mpc. Thus high-redshift quasars are appreciably more strongly clustered than their z ≈ 1.5 counterparts, which have a comoving clustering length r0 ≈ 6.5 h-1 Mpc. Dividing our sample into two redshift bins, 2.9 ≤ z ≤ 3.5 and z ≥ 3.5, and assuming a power-law index γ = 2.0, we find a correlation length of r0 = 16.9 ± 1.7 h-1 Mpc for the former and r0 = 24.3 ± 2.4 h-1 Mpc for the latter. Strong clustering at high redshift indicates that quasars are found in very massive, and therefore highly biased, halos. Following Martini & Weinberg, we relate the clustering strength and quasar number density to the quasar lifetimes and duty cycle. Using the Sheth & Tormen halo mass function, the quasar lifetime is estimated to lie in the range ∼4-50 Myr for quasars with 2.9 ≤ z ≤ 3.5, and ∼30-600 Myr for quasars with z ≥ 3.5. The corresponding duty cycles are ∼0.004-0.05 for the lower redshift bin and ∼0.03-0.6 for the higher redshift bin. The minimum mass of halos in which these quasars reside is (2-3) × 1012 h-1 M⊙ for quasars with 2.9 ≤ z ≤ 3.5 and (4-6) × 1012 h-1 M⊙ for quasars with z ≥ 3.5; the effective bias factor beff increases with redshift, e.g., beff ∼ 8 at z = 3.0 and beff ∼ 16 at z = 4.5.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/708153c0dd41a6092a6e0b709adfef8c18b4d193

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

  1. D. Schneider
  2. L. Hernquist
  3. P. Hopkins
  4. J. Brinkmann
  5. Simon D. M. White
  6. Volker Springel
  7. M. Blanton
  8. Daniel J. Eisenstein

In Instrumentation

  1. D. Schneider
  2. L. Hernquist
  3. P. Hopkins
  4. J. Brinkmann
  5. M. Blanton
  6. C. Conroy
  7. Simon D. M. White
  8. Thomas J. Cox

Citations in the corpus