Baryon acoustic oscillations from the cross-correlation of Ly α absorption and quasars in eBOSS DR14

Michael Blomqvist, Hélion Du Mas Des Bourboux, Nicolás G. Busca, Victoria De Sainte Agathe, James Rich, Christophe Balland, Julian E. Bautista, Kyle Dawson, Andreu Font-Ribera, Julien Guy, Jean Marc Le Goff, Nathalie Palanque-Delabrouille, Will J. Percival, Ignasi Pérez-Ràfols, Matthew M. Pieri, Donald P. Schneider, Anže Slosar, Christophe Yèche

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184 Scopus citations


We present a measurement of the baryon acoustic oscillation (BAO) scale at redshift z = 2.35 from the three-dimensional correlation of Lyman-α (Lyα) forest absorption and quasars. The study uses 266 590 quasars in the redshift range 1.77 < z < 3.5 from the Sloan Digital Sky Survey (SDSS) Data Release 14 (DR14). The sample includes the first two years of observations by the SDSS-IV extended Baryon Oscillation Spectroscopic Survey (eBOSS), providing new quasars and re-observations of BOSS quasars for improved statistical precision. Statistics are further improved by including Lyα absorption occurring in the Lyβ wavelength band of the spectra. From the measured BAO peak position along and across the line of sight, we determined the Hubble distance DH and the comoving angular diameter distance DM relative to the sound horizon at the drag epoch rd: DH(z = 2.35)/rd = 9.20 ± 0.36 and DM(z = 2.35)/rd = 36.3 ± 1.8. These results are consistent at 1.5σ with the prediction of the best-fit spatially-flat cosmological model with the cosmological constant reported for the Planck (2016) analysis of cosmic microwave background anisotropies. Combined with the Lyα auto-correlation measurement presented in a companion paper, the BAO measurements at z = 2.34 are within 1.7σ of the predictions of this model.

Original languageEnglish (US)
Article numberA86
JournalAstronomy and Astrophysics
StatePublished - Sep 1 2019

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


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