Measurement of baryon acoustic oscillation correlations at z = 2.3 with SDSS DR12 Lyα-Forests

¹ Department of Physics and Astronomy, University of Utah, 115 S 1400 E, Salt Lake City, UT 84112, USA
² APC, Université Paris Diderot-Paris 7, CNRS/IN2P3, CEA, Observatoire de Paris, 10 rue A. Domon & L. Duquet, 75013 Paris, France
³ LPNHE, CNRS/IN2P3, Université Pierre et Marie Curie Paris 6, Université Denis Diderot Paris 7, 4 place Jussieu, 75252 Paris CEDEX, France
⁴ IRFU, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
e-mail: rich@hep.saclay.cea.fr
⁵ Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
⁶ Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
⁷ Department of Physics and Astronomy, University College London, Gower Street, London, UK
⁸ Laboratoire d’Astrophysique, École Polytechnique Fedérale de Lausanne, 1015 Lausanne, Switzerland
⁹ Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA
¹⁰ Brookhaven National Laboratory, 2 Center Road, Upton, NY 11973, USA
¹¹ Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA
¹² Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Catalonia, Spain
¹³ Institució de Ciéncies del Cosmos, Universitat de Barcelona (UB-IEEC), 08007 Barcelona, Catalonia, Spain
¹⁴ Université Paris 6 et CNRS, Institut d’Astrophysique de Paris, 98bis boulevard Arago, 75014 Paris, France
¹⁵ Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ, UK
¹⁶ Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802, USA
¹⁷ Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802, USA
¹⁸ Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA

Received: 31 January 2017
Accepted: 20 March 2017

Abstract

We have used flux-transmission correlations in Lyα forests to measure the imprint of baryon acoustic oscillations (BAO). The study uses spectra of 157 783 quasars in the redshift range 2.1 ≤ z ≤ 3.5 from the Sloan Digital Sky Survey (SDSS) data release 12 (DR12). Besides the statistical improvements on our previous studies using SDSS DR9 and DR11, we have implemented numerous improvements in the analysis procedure, allowing us to construct a physical model of the correlation function and to investigate potential systematic errors in the determination of the BAO peak position. The Hubble distance, D_H = c/H(z), relative to the sound horizon is D_H(z = 2.33) /r_d = 9.07 ± 0.31. The best-determined combination of comoving angular-diameter distance, D_M, and the Hubble distance is found to be D_H^0.7D_M^0.3 /r_d = 13.94 ± 0.35. This value is 1.028 ± 0.026 times the prediction of the flat-ΛCDM model consistent with the cosmic microwave background (CMB) anisotropy spectrum. The errors include marginalization over the effects of unidentified high-density absorption systems and fluctuations in ultraviolet ionizing radiation. Independently of the CMB measurements, the combination of our results and other BAO observations determine the open-ΛCDM density parameters to be Ω_M = 0.296 ± 0.029, Ω_Λ = 0.699 ± 0.100 and Ω_k = −0.002 ± 0.119.