Baryon acoustic oscillations at z = 2.34 from the correlations of Lyα absorption in eBOSS DR14

¹ Sorbonne Université, Université Paris Diderot, CNRS/IN2P3, Laboratoire de Physique Nucléaire et de Hautes Energies, LPNHE, 4 Place Jussieu, 75252 Paris, France
e-mail: victoria.de.sainte.agathe@lpnhe.in2p3.fr
² Department of Physics and Astronomy, University of Utah, 115 S. 1400 E., Salt Lake City, UT 84112 USA
³ Aix Marseille Univ., CNRS, CNES, LAM, Marseille, France
⁴ Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
⁵ IRFU, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
⁶ University College London, Gower St, Kings Cross, London WC1E 6BT, UK
⁷ Institute of Cosmology & Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth PO1 3FX, UK
⁸ Instituto de Astronomía, Universidad Nacional Autónoma de México, A.P. 70-264, DF 04510 México, Mexico
⁹ Department of Physics and Astronomy, University of Waterloo, 200 University Ave. W., Waterloo, ON N2L 3G1, Canada
¹⁰ Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA, 16802, USA
¹¹ Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA, 16802, USA
¹² Brookhaven National Laboratory, 2 Center Road, Upton, NY 11973, USA

Received: 8 April 2019
Accepted: 8 July 2019

Abstract

We measure the imprint of primordial baryon acoustic oscillations (BAOs) in the correlation function of Lyα absorption in quasar spectra from the Baryon Oscillation Spectroscopic Survey (BOSS) and the extended BOSS (eBOSS) in Data Release 14 (DR14) of the Sloan Digital Sky Survey (SDSS)-IV. In addition to 179 965 spectra with absorption in the Lyman-α (Lyα) region, we use Lyα absorption in the Lyman-β region of 56 154 spectra for the first time. We measure the Hubble distance, D_H, and the comoving angular diameter distance, D_M, relative to the sound horizon at the drag epoch r_d at an effective redshift z = 2.34. Using a physical model of the correlation function outside the BAO peak, we find D_H(2.34)/r_d = 8.86 ± 0.29 and D_M(2.34)/r_d = 37.41 ± 1.86, within 1σ from the flat-ΛCDM model consistent with CMB anisotropy measurements. With the addition of polynomial “broadband” terms, the results remain within one standard deviation of the CMB-inspired model. Combined with the quasar-Lyα cross-correlation measurement presented in a companion paper, the BAO measurements at z = 2.35 are within 1.7σ of the predictions of this model.