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The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in the Data Release 10 and 11 galaxy samples

Lauren Anderson, Eric Aubourg, Stephen Bailey, Florian Beutler, Vaishali Bhardwaj, Michael Blanton, Adam S. Bolton, J. Brinkmann, Joel R. Brownstein, Angela Burden, Chia-Hsun Chuang, Antonio J. Cuesta, Kyle S. Dawson, Daniel J. Eisenstein, Stephanie Escoffier, James E. Gunn, Hong Guo, Shirley Ho, Klaus Honscheid, Cullan Howlett, David Kirkby, Robert H. Lupton, Marc Manera, Claudia Maraston, Cameron K. McBride, Olga Mena, Francesco Montesano, Robert C. Nichol, Sebastian E. Nuza, Matthew D. Olmstead, Nikhil Padmanabhan, Nathalie Palanque-Delabrouille, John Parejko, Will J. Percival, Patrick Petitjean, Francisco Prada, Adrian M. Price-Whelan, Beth Reid, Natalie A. Roe, Ashley J. Ross, Nicholas P. Ross, Cristiano G. Sabiu, Shun Saito, Lado Samushia, Ariel G. Sanchez, David J. Schlegel, Donald P. Schneider, Claudia G. Scoccola, Hee-Jong Seo, Ramin A. Skibba, Michael A. Strauss, Molly E. C. Swanson, Daniel Thomas, Jeremy L. Tinker, Rita Tojeiro, Mariana Vargas Magana, Licia Verde, David A. Wake, Benjamin A. Weaver, David H. Weinberg, Martin White, Xiaoying Xu, Christophe Yeche, Idit Zehavi, Gong-Bo Zhao

Abstract

We present a one per cent measurement of the cosmic distance scale from the detections of the baryon acoustic oscillations in the clustering of galaxies from the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky Survey III (SDSS-III). Our results come from the Data Release 11 (DR11) sample, containing nearly one million galaxies and covering approximately $8\,500$ square degrees and the redshift range $0.2<z<0.7$. We also compare these results with those from the publicly released DR9 and DR10 samples. Assuming a concordance $Λ$CDM cosmological model, the DR11 sample covers a volume of 13\,Gpc${}^3$ and is the largest region of the Universe ever surveyed at this density. We measure the correlation function and power spectrum, including density-field reconstruction of the baryon acoustic oscillation (BAO) feature. The acoustic features are detected at a significance of over $7\,σ$ in both the correlation function and power spectrum. Fitting for the position of the acoustic features measures the distance relative to the sound horizon at the drag epoch, $r_d$, which has a value of $r_{d,{\rm fid}}=149.28\,$Mpc in our fiducial cosmology. We find $D_V=(1264\pm25\,{\rm Mpc})(r_d/r_{d,{\rm fid}})$ at $z=0.32$ and $D_V=(2056\pm20\,{\rm Mpc})(r_d/r_{d,{\rm fid}})$ at $z=0.57$. At 1.0 per cent, this latter measure is the most precise distance constraint ever obtained from a galaxy survey. Separating the clustering along and transverse to the line-of-sight yields measurements at $z=0.57$ of $D_A=(1421\pm20\,{\rm Mpc})(r_d/r_{d,{\rm fid}})$ and $H=(96.8\pm3.4\,{\rm km/s/Mpc})(r_{d,{\rm fid}}/r_d)$. Our measurements of the distance scale are in good agreement with previous BAO measurements and with the predictions from cosmic microwave background data for a spatially flat cold dark matter model with a cosmological constant.

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in the Data Release 10 and 11 galaxy samples

Abstract

We present a one per cent measurement of the cosmic distance scale from the detections of the baryon acoustic oscillations in the clustering of galaxies from the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky Survey III (SDSS-III). Our results come from the Data Release 11 (DR11) sample, containing nearly one million galaxies and covering approximately square degrees and the redshift range . We also compare these results with those from the publicly released DR9 and DR10 samples. Assuming a concordance CDM cosmological model, the DR11 sample covers a volume of 13\,Gpc and is the largest region of the Universe ever surveyed at this density. We measure the correlation function and power spectrum, including density-field reconstruction of the baryon acoustic oscillation (BAO) feature. The acoustic features are detected at a significance of over in both the correlation function and power spectrum. Fitting for the position of the acoustic features measures the distance relative to the sound horizon at the drag epoch, , which has a value of Mpc in our fiducial cosmology. We find at and at . At 1.0 per cent, this latter measure is the most precise distance constraint ever obtained from a galaxy survey. Separating the clustering along and transverse to the line-of-sight yields measurements at of and . Our measurements of the distance scale are in good agreement with previous BAO measurements and with the predictions from cosmic microwave background data for a spatially flat cold dark matter model with a cosmological constant.

Paper Structure

This paper contains 40 sections, 44 equations, 29 figures, 15 tables.

Table of Contents

  1. Introduction
  2. The Data
  3. SDSS-III BOSS
  4. Galaxy Catalogues
  5. Masks
  6. Weighting galaxies
  7. Analysis changes common to isotropic and anisotropic clustering since DR9
  8. Reconstruction
  9. Mock catalogs
  10. Covariance matrices
  11. Measuring isotropic BAO positions
  12. Methodology
  13. Testing on Mock Galaxy Catalogs
  14. Combining Results from Separate Estimators
  15. Measuring Anisotropic BAO Positions
  16. ...and 25 more sections

Figures (29)

  • Figure 1: Histograms of the galaxy number density as a function of redshift for LOWZ (red) and CMASS (green) samples we analyse. We also display the number density of the SDSS-II DR7 LRG sample in order to illustrate the increase in sample size provided by BOSS LOWZ galaxies.
  • Figure 2: Evolution of the BOSS sky coverage from DR9 to DR11. Top panels show our observations in the North Galactic Cap (NGC) while lower panels show observations in the South Galactic Cap (SGC). Colors indicate the spectroscopic completeness within each sector as indicated in the key in the lower right panel. Gray areas indicate our expected footprint upon completion of the survey. The total sky coverage in DR9, DR10, and DR11 is 3,275 deg$^2$, 6,161 deg$^2$, and 8,377 deg$^2$, respectively.
  • Figure 3: Dependence of the CMASS galaxy surface number density on the density of SDSS stars with $17.5 < i < 19.9$ (panel a), $r$-band Galactic extinction (b) and the $i$-band seeing of the imaging data (c). These lines deviate from $n_g=1$, indicating the presence of systematics affecting the galaxy distribution. We correct for the systematic relationships using weights, with the relationships after applying weights shown in green. The relationship with seeing is dramatic, but only one per cent of the DR11 footprint has $i$-band seeing worse than 1$\farcs6$.
  • Figure 4: Scatter plots of $\sigma_\alpha$ pre- and post-reconstruction: mocks (circles) + data (star) for $\xi$ and $P(k)$ CMASS DR10 and DR11. For the DR11 data, reconstruction improves the precision in each of the 600 mock realisations, for both $\xi(s)$ and $P(k)$.
  • Figure 5: The correlation between recovered $\alpha$ values calculated using different bin centres for the DR11 CMASS reconstructed power spectrum ($P(k)$; left) and correlation function ($\xi(s)$; right). The correlation between bins is of lower amplitude for $\xi(s)$ compared with $P(k)$, implying that combining results across $\xi(s)$ bin centres will improve the precision more than doing the same for $P(k)$.
  • ...and 24 more figures