Baryon Acoustic Oscillations in the Lyα forest of BOSS DR11 quasars - IN2P3 - Institut national de physique nucléaire et de physique des particules Access content directly
Journal Articles Astronomy and Astrophysics - A&A Year : 2015

Baryon Acoustic Oscillations in the Lyα forest of BOSS DR11 quasars

Julian E. Bautista
Nicolás G. Busca
David Kirkby
  • Function : Author
Stephen Bailey
  • Function : Author
Andreu Font-Ribera
  • Function : Author
Anže Slosar
  • Function : Author
Khee-Gan Lee
  • Function : Author
Matthew M. Pieri
  • Function : Author
Éric Aubourg
Michael Blomqvist
  • Function : Author
Jo Bovy
  • Function : Author
Jon Brinkmann
  • Function : Author
William Carithers
  • Function : Author
Kyle S. Dawson
  • Function : Author
Daniel J. Eisenstein
  • Function : Author
Satya Gontcho a Gontcho
  • Function : Author
Jean-Paul Kneib
Daniel Margala
  • Function : Author
Jordi Miralda-Escudé
  • Function : Author
Adam D. Myers
  • Function : Author
Robert C. Nichol
  • Function : Author
Pasquier Noterdaeme
Ross O’connell
  • Function : Author
Matthew D. Olmstead
  • Function : Author
Isabelle Pâris
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  • PersonId : 973398
Nicholas P. Ross
  • Function : Author
David J. Schlegel
  • Function : Author
Donald P. Schneider
  • Function : Author
David H. Weinberg
  • Function : Author
Donald G. York
  • Function : Author

Abstract

We report a detection of the baryon acoustic oscillation (BAO) feature in the flux-correlation function of the Ly{\alpha} forest of high-redshift quasars with a statistical significance of five standard deviations. The study uses 137,562 quasars in the redshift range $2.1\le z \le 3.5$ from the Data Release 11 (DR11) of the Baryon Oscillation Spectroscopic Survey (BOSS) of SDSS-III. This sample contains three times the number of quasars used in previous studies. The measured position of the BAO peak determines the angular distance, $D_A(z=2.34)$ and expansion rate, $H(z=2.34)$, both on a scale set by the sound horizon at the drag epoch, $r_d$. We find $D_A/r_d=11.28\pm0.65(1\sigma)^{+2.8}_{-1.2}(2\sigma)$ and $D_H/r_d=9.18\pm0.28(1\sigma)\pm0.6(2\sigma)$ where $D_H=c/H$. The optimal combination, $\sim D_H^{0.7}D_A^{0.3}/r_d$ is determined with a precision of $\sim2\%$. For the value $r_d=147.4~{\rm Mpc}$, consistent with the CMB power spectrum measured by Planck, we find $D_A(z=2.34)=1662\pm96(1\sigma)~{\rm Mpc}$ and $H(z=2.34)=222\pm7(1\sigma)~{\rm km\,s^{-1}Mpc^{-1}}$. Tests with mock catalogs and variations of our analysis procedure have revealed no systematic uncertainties comparable to our statistical errors. Our results agree with the previously reported BAO measurement at the same redshift using the quasar-Ly{\alpha} forest cross-correlation. The auto-correlation and cross-correlation approaches are complementary because of the quite different impact of redshift-space distortion on the two measurements. The combined constraints from the two correlation functions imply values of $D_A/r_d$ and $D_H/r_d$ that are, respectively, 7% low and 7% high compared to the predictions of a flat $\Lambda$CDM cosmological model with the best-fit Planck parameters. With our estimated statistical errors, the significance of this discrepancy is $\approx 2.5\sigma$.

Dates and versions

in2p3-00976503 , version 1 (14-04-2014)

Identifiers

Cite

Timothée Delubac, Julian E. Bautista, Nicolás G. Busca, James Rich, David Kirkby, et al.. Baryon Acoustic Oscillations in the Lyα forest of BOSS DR11 quasars. Astronomy and Astrophysics - A&A, 2015, 574, pp.A59. ⟨10.1051/0004-6361/201423969⟩. ⟨in2p3-00976503⟩
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