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oai:recercat.cat:2445/1070832025-11-21T05:26:51Zcom_2072_1057col_2072_478904col_2072_478917

00925njm 22002777a 4500 dc Anderson, Lauren author Aubourg, Eric author Bailey, Stephen author Bizyaev, Dmitry author Blanton, Michael R. author Bolton, Adam S. author Brinkmann, Jon author Brownstein, Joel R. author Burden, Angela author Cuesta, Antonio J. author Da Costa, Luiz A. N. author Dawson, Kyle S. author Putter, Roland de author Eisenstein, Daniel J. author Gunn, James E. author Guo, Hong author Hamilton, Jean-Christophe author Harding, Paul author Ho, Shirley author Honscheid, Klaus author Kazin, Eyal A. author Kirkby, David author Kneib, Jean-Paul author Labatie, Antoine author Loomis, Craig author Lupton, Robert H. author Malanushenko, Elena author Malanushenko, Viktor author Mandelbaum, Rachel author Manera, Marc author Maraston, Claudia author McBride, Cameron K. author Mehta, Kushal T. author Mena, Olga author Montesano, Francesco author Muna, Demetri author Nichol, Robert C. author Nuza, Sebastián E. author Olmstead, Matthew D. O author Verde, Licia author 2017-02-17T08:45:49Z 2017-02-17T08:45:49Z 2013-01-29 2017-02-16T16:05:38Z 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 LambdaCDM 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, n¯≈3×10-4 h-3 Mpc 3. 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 5sigma in both the correlation function and power spectrum. Combining with the SDSS-II luminous red galaxy sample, the detection significance increases to 6.7sigma. 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. Energia fosca (Astronomia) Cosmologia Mesurament de les distàncies Astrofísica Observacions astronòmiques Dark energy (Astronomy) Cosmology Measurement of distances Astrophysics Astronomical observations The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: baryon acoustic oscillations in the Data Release 9 spectroscopic galaxy sample