TY - JOUR

T1 - Baryon acoustic oscillations in the Lyα forest of BOSS DR11 quasars

AU - Delubac, Timothée

AU - Bautista, Julian E.

AU - Busca, Nicolás G.

AU - Rich, James

AU - Kirkby, David

AU - Bailey, Stephen

AU - Font-Ribera, Andreu

AU - Slosar, Anže

AU - Lee, Khee-Gan

AU - Pieri, Matthew M.

AU - Hamilton, Jean-Christophe

AU - Aubourg, Éric

AU - Blomqvist, Michael

AU - Bovy, Jo

AU - Brinkmann, J.

AU - Carithers, William

AU - Dawson, Kyle S.

AU - Eisenstein, Daniel J.

AU - Gontcho, Satya Gontcho A

AU - Kneib, Jean-Paul

AU - Goff, J. -M. Le

AU - Margala, Daniel

AU - Miralda-Escudé, Jordi

AU - Myers, Adam D.

AU - Nichol, Robert C.

AU - Noterdaeme, Pasquier

AU - O'Connell, Ross

AU - Olmstead, Matthew D.

AU - Palanque-Delabrouille, Nathalie

AU - Pâris, Isabelle

AU - Petitjean, Patrick

AU - Ross, Nicholas P.

AU - Rossi, Graziano

AU - Schlegel, David J.

AU - Schneider, Donald P.

AU - Weinberg, David H.

AU - Yèche, Christophe

AU - York, Donald G.

PY - 2015/2

Y1 - 2015/2

N2 - 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 $\approx 2.5\sigma$.

AB - 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 $\approx 2.5\sigma$.

KW - astro-ph.CO

KW - cosmology

KW - Lyα forest

KW - large scale structure

KW - dark energy

KW - RCUK

KW - STFC

U2 - 10.1051/0004-6361/201423969

DO - 10.1051/0004-6361/201423969

M3 - Article

SN - 0004-6361

VL - 574

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

M1 - A59

ER -