The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in the Data Release 9 Spectroscopic Galaxy Sample

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2012 RAS © 2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
We present measurements of galaxy clustering from the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky Survey III (SDSS-III). These use the Data Release 9 (DR9) CMASS sample, which contains 264 283 massive galaxies covering 3275 square degrees with an effective redshift z = 0.57 and redshift range 0.43 < z < 0.7. Assuming a concordance λCDM cosmological model, this sample covers an effective volume of 2.2 Gpc3, and represents the largest sample of the Universe ever surveyed at this density, n̄ ~3 × 10-4 h-3 Mpc3. We measure the angle-averaged galaxy correlation function and power spectrum, including density-field reconstruction of the baryon acoustic oscillation (BAO) feature. The acoustic features are detected at a significance of 5σ in both the correlation function and power spectrum. Combining with the SDSS-II luminous red galaxy sample, the detection significance increases to 6.7σ. Fitting for the position of the acoustic features measures the distance to z = 0.57 relative to the sound horizon DV/rs = 13.67 ± 0.22 at z = 0.57. Assuming a fiducial sound horizon of 153.19 Mpc, which matches cosmic microwave background constraints, this corresponds to a distance DV (z = 0.57) = 2094 ± 34 Mpc. At 1.7 per cent, this is the most precise distance constraint ever obtained from a galaxy survey. We place this result alongside previous BAO measurements in a cosmological distance ladder and find excellent agreement with the current supernova measurements. We use these distance measurements to constrain various cosmological models, finding continuing support for a flat Universe with a cosmological constant
WJP is grateful for support from the UK Science and Technology Facilities Research Council, the Leverhulme Trust, and the European Research Council.AJR is grateful to theUKScience and Technology Facilities Council for financial support through the grant ST/I001204/1. CGS acknowledges funding from project AYA2010- 21766-C03-02 of the Spanish Ministry of Science and Innovation (MICINN). DJE, XX, and KM were supported by NSF grant AST-0707725 and NASA grant NNX07AH11G. NP and AJC are partially supported by NASA grant NNX11AF43G. FP acknowledges support from the SpanishMICINNs Consolider grantMultiDark CSD2009- 00064. MAS was supported by NSF grant AST-0707266. MECS was supported by the NSF under Award No. AST-0901965. Support for LAMBDA is provided by the NASA Office of Space Science