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The real-space clustering of luminous red galaxies around z < 0.6 quasars in the Sloan Digital Sky Survey

Padmanabhan, Nikhil ; White, Martin ; Norberg, Peder ; Porciani, Cristiano

In: Monthly Notices of the Royal Astronomical Society, 2009, vol. 397, no. 4, p. 1862-1875

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    Titre
    • The real-space clustering of luminous red galaxies around z < 0.6 quasars in the Sloan Digital Sky Survey
    Auteur
    • Padmanabhan, Nikhil. Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, USA
    • White, Martin. Department of Physics and Astronomy, 601 Campbell Hall, University of California Berkeley, CA 94720, USA
    • Norberg, Peder. The Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ
    • Porciani, Cristiano. Institute for Astronomy, ETH Zurich, 8093 Zurich, Switzerland
    Type de document
    • Postprint
    Langue
    • Inglese
    Publié dans
    • Monthly Notices of the Royal Astronomical Society, 2009, vol. 397, no. 4, p. 1862-1875. Blackwell Publishing Ltd
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:298100
    Summary
    We measure the clustering of a sample of photometrically selected luminous red galaxies (LRGs) around a low-redshift (0.2 < z < 0.6) sample of quasars selected from the Sloan Digital Sky Survey Data Release 5. We make use of a new statistical estimator to obtain precise measurements of the LRG autocorrelations and constrain halo occupation distributions for them. These are used to generate mock catalogues which aid in interpreting our quasar-LRG cross-correlation measurements. The cross-correlation is well described by a power law with slope 1.8 ± 0.1 and r0= 6 ± 0.5 h−1 Mpc, consistent with observed galaxy correlation functions. We find no evidence for ‘excess' clustering on 0.1 Mpc scales and demonstrate that this is consistent with the results of Serber et al. and Strand, Brunner and Myers, when one accounts for several subtleties in the interpretation of their measurements. Combining the quasar-LRG cross-correlation with the LRG autocorrelations, we determine a large-scale quasar bias bQSO= 1.09 ± 0.15 at a median redshift of 0.43, with no observed redshift or luminosity evolution. This corresponds to a mean halo mass 〈M〉∼ 1012 h−1 M⊙, Eddington ratios from 0.01 to 1 and lifetimes less than 107 yr. Using simple models of halo occupation, these correspond to a number density of quasar hosts greater than 10−3h3 Mpc−3 and stellar masses less than 1011h−1 M⊙. The small-scale clustering signal can be interpreted with the aid of our mock LRG catalogues, and depends on the manner in which quasars inhabit haloes. We find that our small-scale measurements are inconsistent with quasar positions being randomly subsampled from halo centres above a mass threshold, requiring a satellite fraction >25 per cent