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Title: THE SLOAN DIGITAL SKY SURVEY QUASAR LENS SEARCH. VI. CONSTRAINTS ON DARK ENERGY AND THE EVOLUTION OF MASSIVE GALAXIES

Journal Article · · Astronomical Journal (New York, N.Y. Online)
; ;  [1];  [2]; ; ;  [3];  [4];  [5];  [6];  [7];  [8];  [9];  [10];  [11]
  1. Institute for the Physics and Mathematics of the Universe, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan)
  2. Department of Physics, Nara National College of Technology, Yamatokohriyama, Nara 639-1080 (Japan)
  3. Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States)
  4. Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)
  5. Institute of Astronomy, School of Science, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan)
  6. Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)
  7. Optical and Infrared Astronomy Division, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
  8. Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States)
  9. Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)
  10. Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
  11. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

We present a statistical analysis of the final lens sample from the Sloan Digital Sky Survey Quasar Lens Search (SQLS). The number distribution of a complete subsample of 19 lensed quasars selected from 50,836 source quasars is compared with theoretical expectations, with particular attention given to the selection function. Assuming that the velocity function of galaxies does not evolve with redshift, the SQLS sample constrains the cosmological constant to {Omega}{sub {Lambda}} = 0.79{sup +0.06}{sub -0.07}(stat.){sup +0.06}{sub -0.06}(syst.) for a flat universe. The dark energy equation of state is found to be consistent with w = -1 when the SQLS is combined with constraints from baryon acoustic oscillation (BAO) measurements or results from the Wilkinson Microwave Anisotropy Probe (WMAP). We also obtain simultaneous constraints on cosmological parameters and redshift evolution of the galaxy velocity function, finding no evidence for redshift evolution at z {approx}< 1 in any combinations of constraints. For instance, number density evolution quantified as {nu}{sub n} {identical_to} dln {phi}{sub *}/dln (1 + z) and the velocity dispersion evolution {nu}{sub {sigma}} {identical_to} dln {sigma}{sub *}/dln (1 + z) are constrained to {nu}{sub n} = 1.06{sup +1.36}{sub -1.39}(stat.){sup +0.33}{sub -0.64}(syst.) and {nu}{sub {sigma}} = -0.05{sup +0.19}{sub -0.16}(stat.){sup +0.03}{sub -0.03}(syst.), respectively, when the SQLS result is combined with BAO and WMAP for flat models with a cosmological constant. We find that a significant amount of dark energy is preferred even after fully marginalizing over the galaxy evolution parameters. Thus, the statistics of lensed quasars robustly confirm the accelerated cosmic expansion.

OSTI ID:
22034633
Journal Information:
Astronomical Journal (New York, N.Y. Online), Vol. 143, Issue 5; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
Country of Publication:
United States
Language:
English