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 -