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Baryon acoustic oscillations in the Sloan Digital Sky Survey Data Release 7 galaxy sample

Will J. PercivalInstitute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama building, Portsmouth P01 3FXBeth ReidInstitute of Space Sciences (CSIC-IEEC), UAB, Barcelona 08193, SpainDaniel J. EisensteinSteward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85121, USANeta A. BahcallDepartment of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USATamás BudaváriDepartment of Physics and Astronomy, The Johns Hopkins University, 3701 San Martin Drive, Baltimore, MD 21218, USAJoshua A. FriemanParticle Astrophysics Center, Fermilab, PO Box 500, Batavia, IL 60510, USAM. FukugitaInstitute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, JapanJames E. GunnDepartment of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USAŽeljko IvezićDepartment of Astronomy, University of Washington Box 351580, Seattle, WA 98195, USAG. R. KnappDepartment of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USARichard G. KronDepartment of Astronomy and Astrophysics, The University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USAJ. LovedayAstronomy Centre, University of Sussex, Falmer, Brighton BN1 9QHRobert H. LuptonDepartment of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USATimothy A. McKayDepartments of Physics and Astronomy, University of Michigan, Ann Arbor, MI 48109, USAAvery MeiksinInstitute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJRobert C. NicholInstitute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama building, Portsmouth P01 3FXAdrian PopeLos Alamos National Laboratory, PO Box 1663, Los Alamos, NM 87545, USADavid J. SchlegelLawrence Berkeley National Lab, 1 Cyclotron Road, MS 50R5032, Berkeley, CA 94720, USADonald P. SchneiderDepartment of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802, USADavid N. SpergelPrinceton Center for Theoretical Science, Princeton University, Jadwin Hall, Princeton, NJ 08542, USAChris StoughtonFermilab, PO Box 500, Batavia, IL 60510, USAMichael A. StraussDepartment of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USAAlexander S. SzalayDepartment of Physics and Astronomy, The Johns Hopkins University, 3701 San Martin Drive, Baltimore, MD 21218, USAMax TegmarkDepartment of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USAMichael S. VogeleyDepartment of Physics, Drexel University, Philadelphia, PA 19104, USADavid H. WeinbergDepartment of Astronomy, The Ohio State University, Columbus, OH 43210, USADonald G. YorkEnrico Fermi Institute, University of Chicago, Chicago, IL 60637, USAIdit ZehaviDepartment of Astronomy, Case Western Reserve University, Cleveland, OH 44106, USA

2009en

ABI

Аннотация

The spectroscopic Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) galaxy sample represents the final set of galaxies observed using the original SDSS target selection criteria. We analyse the clustering of galaxies within this sample, including both the luminous red galaxy and main samples, and also include the 2-degree Field Galaxy Redshift Survey data. In total, this sample comprises 893 319 galaxies over 9100 deg2. Baryon acoustic oscillations (BAO) are observed in power spectra measured for different slices in redshift; this allows us to constrain the distance–redshift relation at multiple epochs. We achieve a distance measure at redshift <it>z</it>= 0.275, of <it>r</it><inf>s</inf>(<it>z</it><inf>d</inf>)/<it>D<inf>V</inf></it>(0.275) = 0.1390 ± 0.0037 (2.7 per cent accuracy), where <it>r</it><inf>s</inf>(<it>z</it><inf>d</inf>) is the comoving sound horizon at the baryon-drag epoch, <it>D<inf>V</inf></it>(<it>z</it>) ≡[(1 +<it>z</it>)2<it>D</it>2<inf>A</inf><it>cz</it>/<it>H</it>(<it>z</it>)]1/3, <it>D</it><inf>A</inf>(<it>z</it>) is the angular diameter distance and <it>H</it>(<it>z</it>) is the Hubble parameter. We find an almost independent constraint on the ratio of distances <it>D<inf>V</inf></it>(0.35)/<it>D<inf>V</inf></it>(0.2) = 1.736 ± 0.065, which is consistent at the 1.1σ level with the best-fitting Λ cold dark matter model obtained when combining our <it>z</it>= 0.275 distance constraint with the <it>Wilkinson Microwave Anisotropy Probe</it> 5-year (<it>WMAP</it>5) data. The offset is similar to that found in previous analyses of the SDSS DR5 sample, but the discrepancy is now of lower significance, a change caused by a revised error analysis and a change in the methodology adopted, as well as the addition of more data. Using <it>WMAP</it>5 constraints on Ω<inf>b</inf><it>h</it>2 and Ω<inf>c</inf> <it>h</it>2, and combining our BAO distance measurements with those from the Union supernova sample, places a tight constraint on Ω<inf>m</inf>= 0.286 ± 0.018 and <it>H</it><inf>0</inf>= 68.2 ± 2.2 km s−1 Mpc−1 that is robust to allowing Ω<inf>k</inf>≠ 0 and <it>w</it>≠−1. This result is independent of the behaviour of dark energy at redshifts greater than those probed by the BAO and supernova measurements. Combining these data sets with the full <it>WMAP</it>5 likelihood constraints provides tight constraints on both Ω<inf>k</inf>=−0.006 ± 0.008 and <it>w</it>=−0.97 ± 0.10 for a constant dark energy equation of state.

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DOI: 10.1111/j.1365-2966.2009.15812.x

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