Showing 1–23 of 23 results for author: Montesano, F

The HETDEX Instrumentation: Hobby-Eberly Telescope Wide Field Upgrade and VIRUS

Authors: Gary J. Hill, Hanshin Lee, Phillip J. MacQueen, Andreas Kelz, Niv Drory, Brian L. Vattiat, John M. Good, Jason Ramsey, Herman Kriel, Trent Peterson, D. L. DePoy, Karl Gebhardt, J. L. Marshall, Sarah E. Tuttle, Svend M. Bauer, Taylor S. Chonis, Maximilian H. Fabricius, Cynthia Froning, Marco Haeuser, Briana L. Indahl, Thomas Jahn, Martin Landriau, Ron Leck, Francesco Montesano, Travis Prochaska , et al. (24 additional authors not shown)

Abstract: The Hobby-Eberly Telescope (HET) Dark Energy Experiment (HETDEX) is undertaking a blind wide-field low-resolution spectroscopic survey of 540 square degrees of sky to identify and derive redshifts for a million Lyman-alpha emitting galaxies (LAEs) in the redshift range 1.9 < z < 3.5. The ultimate goal is to measure the expansion rate of the Universe at this epoch, to sharply constrain cosmological… ▽ More The Hobby-Eberly Telescope (HET) Dark Energy Experiment (HETDEX) is undertaking a blind wide-field low-resolution spectroscopic survey of 540 square degrees of sky to identify and derive redshifts for a million Lyman-alpha emitting galaxies (LAEs) in the redshift range 1.9 < z < 3.5. The ultimate goal is to measure the expansion rate of the Universe at this epoch, to sharply constrain cosmological parameters and thus the nature of dark energy. A major multi-year wide field upgrade (WFU) of the HET was completed in 2016 that substantially increased the field of view to 22 arcminutes diameter and the pupil to 10 meters, by replacing the optical corrector, tracker, and prime focus instrument package and by developing a new telescope control system. The new, wide-field HET now feeds the Visible Integral-field Replicable Unit Spectrograph (VIRUS), a new low-resolution integral field spectrograph (LRS2), and the Habitable Zone Planet Finder (HPF), a precision near-infrared radial velocity spectrograph. VIRUS consists of 156 identical spectrographs fed by almost 35,000 fibers in 78 integral field units arrayed at the focus of the upgraded HET. VIRUS operates in a bandpass of 3500-5500 Angstroms with resolving power R~800. VIRUS is the first example of large scale replication applied to instrumentation in optical astronomy to achieve spectroscopic surveys of very large areas of sky. This paper presents technical details of the HET WFU and VIRUS, as flowed-down from the HETDEX science requirements, along with experience from commissioning this major telescope upgrade and the innovative instrumentation suite for HETDEX. △ Less

Submitted 7 December, 2021; v1 submitted 7 October, 2021; originally announced October 2021.

Comments: 65 pages, 25 figures, published in the Astronomical Journal; replaced with final published version

Journal ref: AJ 162 298 (2021)

The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Cosmological implications of the Fourier space wedges of the final sample

Authors: Jan Niklas Grieb, Ariel G. Sánchez, Salvador Salazar-Albornoz, Román Scoccimarro, Martín Crocce, Claudio Dalla Vecchia, Francesco Montesano, Héctor Gil-Marín, Ashley J. Ross, Florian Beutler, Sergio Rodríguez-Torres, Chia-Hsun Chuang, Francisco Prada, Francisco-Shu Kitaura, Antonio J. Cuesta, Daniel J. Eisenstein, Will J. Percival, Mariana Vargas-Magana, Jeremy L. Tinker, Rita Tojeiro, Joel R. Brownstein, Claudia Maraston, Robert C. Nichol, Matthew D. Olmstead, Lado Samushia , et al. (3 additional authors not shown)

Abstract: We extract cosmological information from the anisotropic power spectrum measurements from the recently completed Baryon Oscillation Spectroscopic Survey (BOSS), extending the concept of clustering wedges to Fourier space. Making use of new FFT-based estimators, we measure the power spectrum clustering wedges of the BOSS sample by filtering out the information of Legendre multipoles l > 4. Our mode… ▽ More We extract cosmological information from the anisotropic power spectrum measurements from the recently completed Baryon Oscillation Spectroscopic Survey (BOSS), extending the concept of clustering wedges to Fourier space. Making use of new FFT-based estimators, we measure the power spectrum clustering wedges of the BOSS sample by filtering out the information of Legendre multipoles l > 4. Our modelling of these measurements is based on novel approaches to describe non-linear evolution, bias, and redshift-space distortions, which we test using synthetic catalogues based on large-volume N-body simulations. We are able to include smaller scales than in previous analyses, resulting in tighter cosmological constraints. Using three overlapping redshift bins, we measure the angular diameter distance, the Hubble parameter, and the cosmic growth rate, and explore the cosmological implications of our full shape clustering measurements in combination with CMB and SN Ia data. Assuming a ΛCDM cosmology, we constrain the matter density to Ω_m = 0.311 -0.010 +0.009 and the Hubble parameter to H_0 = 67.6 -0.6 +0.7 km s^-1 Mpc^-1, at a confidence level (CL) of 68 per cent. We also allow for non-standard dark energy models and modifications of the growth rate, finding good agreement with the ΛCDM paradigm. For example, we constrain the equation-of-state parameter to w = -1.019 -0.039 +0.048. This paper is part of a set that analyses the final galaxy clustering dataset from BOSS. The measurements and likelihoods presented here are combined with others in Alam et al. 2016 to produce the final cosmological constraints from BOSS. △ Less

Submitted 11 November, 2016; v1 submitted 11 July, 2016; originally announced July 2016.

Comments: 23 pages, 16 figures in the main text, appendix of 6 pages and 5 figures; revision submitted to MNRAS. The data used in this analysis is publicly available at https://www.sdss3.org/science/boss_publications.php

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: mock galaxy catalogues for the low-redshift sample

Authors: Marc Manera, Lado Samushia, Rita Tojeiro, Cullan Howlett, Ashley J. Ross, Will J. Percival, Hector Gil-Marín, Joel R. Brownstein, Angela Burden, Francesco Montesano

Abstract: We present one thousand mock galaxy catalogues for the analysis of the Low Redshift Sample (LOWZ, effective redshift z ~ 10.32) of the Baryon Oscillation Spectroscopic Survey Data Releases 10 and 11. These mocks have been created following the PTHalos method of Manera13 et al. (2013) revised to include new developments. The main improvement is the introduction of a redshift dependence in the Halo… ▽ More We present one thousand mock galaxy catalogues for the analysis of the Low Redshift Sample (LOWZ, effective redshift z ~ 10.32) of the Baryon Oscillation Spectroscopic Survey Data Releases 10 and 11. These mocks have been created following the PTHalos method of Manera13 et al. (2013) revised to include new developments. The main improvement is the introduction of a redshift dependence in the Halo Occupation Distribution in order to account for the change of the galaxy number density with redshift. These mock catalogues are used in the analyses of the LOWZ galaxy clustering by the BOSS collaboration. △ Less

Submitted 16 January, 2014; originally announced January 2014.

Comments: 10 pages, 8 figures

Journal ref: Monthly Notices of the Royal Astronomical Society 2014 447 (3): 437-445

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: galaxy clustering measurements in the low redshift sample of Data Release 11

Authors: Rita Tojeiro, Ashley J. Ross, Angela Burden, Lado Samushia, Marc Manera, Will J. Percival, Florian Beutler, Antonio J. Cuesta, Kyle Dawson, Daniel J. Eisenstein, Shirley Ho, Cullan Howett, Cameron K. McBride, Francisco Montesano, John K. Parejko, Beth Reid, Ariel G. Sánchez, David J. Schlegel, Donald P. Schneider, Jeremy L. Tinker, Mariana Vargas Magaña, Martin White

Abstract: We present the distance measurement to z = 0.32 using the 11th data release of the Sloan Digital Sky Survey-III Baryon Acoustic Oscillation Survey (BOSS). We use 313,780 galaxies of the low-redshift (LOWZ) sample over 7,341 square-degrees to compute $D_V = (1264 \pm 25)(r_d/r_{d,fid})$ - a sub 2% measurement - using the baryon acoustic feature measured in the galaxy two-point correlation function… ▽ More We present the distance measurement to z = 0.32 using the 11th data release of the Sloan Digital Sky Survey-III Baryon Acoustic Oscillation Survey (BOSS). We use 313,780 galaxies of the low-redshift (LOWZ) sample over 7,341 square-degrees to compute $D_V = (1264 \pm 25)(r_d/r_{d,fid})$ - a sub 2% measurement - using the baryon acoustic feature measured in the galaxy two-point correlation function and power-spectrum. We compare our results to those obtained in DR10. We study observational systematics in the LOWZ sample and quantify potential effects due to photometric offsets between the northern and southern Galactic caps. We find the sample to be robust to all systematic effects found to impact on the targeting of higher-redshift BOSS galaxies, and that the observed north-south tensions can be explained by either limitations in photometric calibration or by sample variance, and have no impact on our final result. Our measurement, combined with the baryonic acoustic scale at z = 0.57, is used in Anderson et al. (2013a) to constrain cosmological parameters. △ Less

Submitted 8 January, 2014; originally announced January 2014.

Comments: 17 pages. Submitted to MNRAS

The Clustering of Galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS): measuring growth rate and geometry with anisotropic clustering

Authors: Lado Samushia, Beth A. Reid, Martin White, Will J. Percival, Antonio J. Cuesta, Gong-Bo Zhao, Ashley J. Ross, Marc Manera, Éric Aubourg, Florian Beutler, Jon Brinkmann, Joel R. Brownstein, Kyle S. Dawson, Daniel J. Eisenstein, Shirley Ho, Klaus Honscheid, Claudia Maraston, Francesco Montesano, Robert C. Nichol, Natalie A. Roe, Nicholas P. Ross, Ariel G. Sánchez, David J. Schlegel, Donald P. Schneider, Alina Streblyanska , et al. (5 additional authors not shown)

Abstract: We use the observed anisotropic clustering of galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 11 CMASS sample to measure the linear growth rate of structure, the Hubble expansion rate and the comoving distance scale. Our sample covers 8498 ${\rm deg}^2$ and encloses an effective volume of 6.0 ${\rm Gpc}^3$ at an effective redshift of $\bar{z} = 0.57$. We find… ▽ More We use the observed anisotropic clustering of galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 11 CMASS sample to measure the linear growth rate of structure, the Hubble expansion rate and the comoving distance scale. Our sample covers 8498 ${\rm deg}^2$ and encloses an effective volume of 6.0 ${\rm Gpc}^3$ at an effective redshift of $\bar{z} = 0.57$. We find $fσ_8 = 0.441 \pm 0.044$, $H = 93.1 \pm 3.0\ {\mathrm{km}\ \mathrm{s}^{-1} \mathrm{Mpc}^{-1}}$ and $D_{\rm A} = 1380 \pm 23\ {\rm Mpc}$ when fitting the growth and expansion rate simultaneously. When we fix the background expansion to the one predicted by spatially-flat $Λ$CDM model in agreement with recent Planck results, we find $fσ_8 = 0.447 \pm 0.028$ (6 per cent accuracy). While our measurements are generally consistent with the predictions of $Λ$CDM and General Relativity, they mildly favor models in which the strength of gravitational interactions is weaker than what is predicted by General Relativity. Combining our measurements with recent cosmic microwave background data results in tight constraints on basic cosmological parameters and deviations from the standard cosmological model. Separately varying these parameters, we find $w = -0.983 \pm 0.075$ (8 per cent accuracy) and $γ= 0.69 \pm 0.11$ (16 per cent accuracy) for the effective equation of state of dark energy and the growth rate index, respectively. Both constraints are in good agreement with the standard model values of $w=-1$ and $γ= 0.554$. △ Less

Submitted 13 May, 2014; v1 submitted 17 December, 2013; originally announced December 2013.

Comments: 17 pages, 18 figures, published in MNRAS. Minor modifications to match the published version

Journal ref: Monthly Notices of the Royal Astronomical Society, Volume 439, Issue 4, p.3504-3519 (2014)

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

Authors: 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 , et al. (40 additional authors not shown)

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… ▽ More 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. △ Less

Submitted 3 June, 2014; v1 submitted 17 December, 2013; originally announced December 2013.

Comments: 40 pages, 29 figures; replaced with final version in journal

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological implications of the full shape of the clustering wedges in the data release 10 and 11 galaxy samples

Authors: Ariel G. Sanchez, Francesco Montesano, Eyal A. Kazin, Eric Aubourg, Florian Beutler, Jon Brinkmann, Joel R. Brownstein, Antonio J. Cuesta, Kyle S. Dawson, Daniel J. Eisenstein, Shirley Ho, Klaus Honscheid, Marc Manera, Claudia Maraston, Cameron K. McBride, Will J. Percival, Ashley J. Ross, Lado Samushia, David J. Schlegel, Donald P. Schneider, Ramin Skibba, Daniel Thomas, Jeremy L. Tinker, Rita Tojeiro, David A. Wake , et al. (3 additional authors not shown)

Abstract: We explore the cosmological implications of the angle-averaged correlation function, xi(s), and the clustering wedges, xi_perp(s) and xi_para(s), of the LOWZ and CMASS galaxy samples from Data Release 10 and 11 of the SDSS-III Baryon Oscillation Spectroscopic Survey. Our results show no significant evidence for a deviation from the standard LCDM model. The combination of the information from our c… ▽ More We explore the cosmological implications of the angle-averaged correlation function, xi(s), and the clustering wedges, xi_perp(s) and xi_para(s), of the LOWZ and CMASS galaxy samples from Data Release 10 and 11 of the SDSS-III Baryon Oscillation Spectroscopic Survey. Our results show no significant evidence for a deviation from the standard LCDM model. The combination of the information from our clustering measurements with recent data from the cosmic microwave background is sufficient to constrain the curvature of the Universe to Omega_k = 0.0010 +- 0.0029, the total neutrino mass to Sum m_nu < 0.23 eV (95% confidence level), the effective number of relativistic species to N_eff=3.31 +- 0.27, and the dark energy equation of state to w_DE = -1.051 +- 0.076. These limits are further improved by adding information from type Ia supernovae and baryon acoustic oscillations from other samples. In particular, this data set combination is completely consistent with a time-independent dark energy equation of state, in which case we find w_DE=-1.024 +- 0.052. We explore the constraints on the growth-rate of cosmic structures assuming f(z)=Omega_m(z)^gamma and obtain gamma=0.69 +- 0.15, in agreement with the predictions from general relativity of gamma=0.55. △ Less

Submitted 17 December, 2013; originally announced December 2013.

Comments: 24 pages, 14 figures. Submitted to MNRAS. Measurements and covariance matrices are available at https://sdss3.org/science/boss_publications.php

The Clustering of Galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Including covariance matrix errors

Authors: Will J. Percival, Ashley J. Ross, Ariel G. Sanchez, Lado Samushia, Angela Burden, Robert Crittenden, Antonio J. Cuesta, Mariana Vargas Magana, Marc Manera, Florian Beutler, Chia-Hsun Chuang, Daniel J. Eisenstein, Shirley Ho, Cameron K. McBride, Francesco Montesano, Nikhil Padmanabhan, Beth Reid, Shun Saito, Donald P. Schneider, Hee-Jong Seo, Rita Tojeiro, Benjamin A. Weaver

Abstract: We present improved methodology for including covariance matrices in the error budget of Baryon Oscillation Spectroscopic Survey (BOSS) galaxy clustering measurements, revisiting Data Release 9 (DR9) analyses, and describing a method that is used in DR10/11 analyses presented in companion papers. The precise analysis method adopted is becoming increasingly important, due to the precision that BOSS… ▽ More We present improved methodology for including covariance matrices in the error budget of Baryon Oscillation Spectroscopic Survey (BOSS) galaxy clustering measurements, revisiting Data Release 9 (DR9) analyses, and describing a method that is used in DR10/11 analyses presented in companion papers. The precise analysis method adopted is becoming increasingly important, due to the precision that BOSS can now reach: even using as many as 600 mock catalogues to estimate covariance of 2-point clustering measurements can still lead to an increase in the errors of ~20%, depending on how the cosmological parameters of interest are measured. In this paper we extend previous work on this contribution to the error budget, deriving formulae for errors measured by integrating over the likelihood, and to the distribution of recovered best-fit parameters fitting the simulations also used to estimate the covariance matrix. Both are situations that previous analyses of BOSS have considered. We apply the formulae derived to Baryon Acoustic Oscillation (BAO) and Redshift-Space Distortion (RSD) measurements from BOSS in our companion papers. To further aid these analyses, we consider the optimum number of bins to use for 2-point measurements using the monopole power spectrum or correlation function for BAO, and the monopole and quadrupole moments of the correlation function for anisotropic-BAO and RSD measurements. △ Less

Submitted 17 December, 2013; originally announced December 2013.

Comments: 11 pages, 5 figures, MNRAS submitted

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Testing gravity with redshift-space distortions using the power spectrum multipoles

Authors: Florian Beutler, Shun Saito, Hee-Jong Seo, Jon Brinkmann, Kyle S. Dawson, Daniel J. Eisenstein, Andreu Font-Ribera, Shirley Ho, Cameron K. McBride, Francesco Montesano, Will J. Percival, Ashley J. Ross, Nicholas P. Ross, Lado Samushia, David J. Schlegel, Ariel G. Sánchez, Jeremy L. Tinker, Benjamin A. Weaver

Abstract: We analyse the anisotropic clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS Data Release 11 (DR11) sample, which consists of $690\,827$ galaxies in the redshift range $0.43 < z < 0.7$ and has a sky coverage of $8\,498\,\text{deg}^2$. We perform our analysis in Fourier space using a power spectrum estimator suggested by Yamamoto et al. (2006). We measure the multipole power sp… ▽ More We analyse the anisotropic clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS Data Release 11 (DR11) sample, which consists of $690\,827$ galaxies in the redshift range $0.43 < z < 0.7$ and has a sky coverage of $8\,498\,\text{deg}^2$. We perform our analysis in Fourier space using a power spectrum estimator suggested by Yamamoto et al. (2006). We measure the multipole power spectra in a self-consistent manner for the first time in the sense that we provide a proper way to treat the survey window function and the integral constraint, without the commonly used assumption of an isotropic power spectrum and without the need to split the survey into sub-regions. The main cosmological signals exploited in our analysis are the Baryon Acoustic Oscillations and the signal of redshift space distortions, both of which are distorted by the Alcock-Paczynski effect. Together, these signals allow us to constrain the distance ratio $D_V(z_{\rm eff})/r_s(z_d) = 13.89\pm 0.18$, the Alcock-Paczynski parameter $F_{\rm AP}(z_{\rm eff}) = 0.679\pm0.031$ and the growth rate of structure $f(z_{\rm eff})σ_8(z_{\rm eff}) = 0.419\pm0.044$ at the effective redshift $z_{\rm eff}=0.57$. We did not find significant systematic uncertainties for $D_V/r_s$ or $F_{\rm AP}$ but include a systematic error for $fσ_8$ of $3.1\%$. Combining our dataset with Planck to test General Relativity (GR) through the simple $γ$-parameterisation, reveals a $\sim 2σ$ tension between the data and the prediction by GR. The tension between our result and GR can be traced back to a tension in the clustering amplitude $σ_8$ between CMASS and Planck. △ Less

Submitted 28 June, 2014; v1 submitted 16 December, 2013; originally announced December 2013.

Comments: 30 pages, 3 Tables, 17 Figures

The Clustering of Galaxies in the SDSS-III DR10 Baryon Oscillation Spectroscopic Survey: No Detectable Colour Dependence of Distance Scale or Growth Rate Measurements

Authors: Ashley J. Ross, Lado Samushia, Angela Burden, Will J. Percival, Rita Tojeiro, Marc Manera, Florian Beutler, J. Brinkmann, Joel R. Brownstein, Aurelio Carnero, Luiz A. N. da Costa, Daniel J. Eisenstein, Hong Guo, Shirley Ho, Marcio A. G. Maia, Francesco Montesano, Demitri Muna, Robert C. Nichol, Sebastian E. Nuza, Ariel G. Sanchez, Donald P. Schneider, Ramin A. Skibba, Flavia Sobreira, Alina Streblyanska, Molly E. C. Swanson , et al. (5 additional authors not shown)

Abstract: We study the clustering of galaxies, as a function of their colour, from Data Release Ten (DR10) of the SDSS-III Baryon Oscillation Spectroscopic Survey. We select 122,967 galaxies with 0.43 < z < 0.7 into a "Blue" sample and 131,969 into a "Red" sample based on k+e corrected (to z=0.55) r-i colours and i band magnitudes. The samples are chosen to each contain more than 100,000 galaxies, have simi… ▽ More We study the clustering of galaxies, as a function of their colour, from Data Release Ten (DR10) of the SDSS-III Baryon Oscillation Spectroscopic Survey. We select 122,967 galaxies with 0.43 < z < 0.7 into a "Blue" sample and 131,969 into a "Red" sample based on k+e corrected (to z=0.55) r-i colours and i band magnitudes. The samples are chosen to each contain more than 100,000 galaxies, have similar redshift distributions, and maximize the difference in clustering amplitude. The Red sample has a 40% larger bias than the Blue (b_Red/b_Blue = 1.39+-0.04), implying the Red galaxies occupy dark matter halos with an average mass that is 0.5 log Mo greater. Spherically averaged measurements of the correlation function, ξ0, and the power spectrum are used to locate the position of the baryon acoustic oscillation (BAO) feature of both samples. Using ξ0, we obtain distance scales, relative to our reference LCDM cosmology, of 1.010+-0.027 for the Red sample and 1.005+-0.031 for the Blue. After applying reconstruction, these measurements improve to 1.013+/-0.020 for the Red sample and 1.008+-0.026 for the Blue. For each sample, measurements of ξ0 and the second multipole moment, ξ2, of the anisotropic correlation function are used to determine the rate of structure growth, parameterized by fσ8. We find fσ8,Red = 0.511+-0.083, fσ8,Blue = 0.509+/-0.085, and fσ8,Cross = 0.423+-0.061 (from the cross-correlation between the Red and Blue samples). We use the covariance between the bias and growth measurements obtained from each sample and their cross-correlation to produce an optimally-combined measurement of fσ8,comb = 0.443+-0.055. In no instance do we detect significant differences in distance scale or structure growth measurements obtained from the Blue and Red samples. △ Less

Submitted 28 October, 2013; v1 submitted 3 October, 2013; originally announced October 2013.

Comments: Accepted by MNRAS, typos fixed, references updated

The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment

Authors: Christopher P. Ahn, Rachael Alexandroff, Carlos Allende Prieto, Friedrich Anders, Scott F. Anderson, Timothy Anderton, Brett H. Andrews, Éric Aubourg, Stephen Bailey, Fabienne A. Bastien, Julian E. Bautista, Timothy C. Beers, Alessandra Beifiori, Chad F. Bender, Andreas A. Berlind, Florian Beutler, Vaishali Bhardwaj, Jonathan C. Bird, Dmitry Bizyaev, Cullen H. Blake, Michael R. Blanton, Michael Blomqvist, John J. Bochanski, Adam S. Bolton, Arnaud Borde , et al. (210 additional authors not shown)

Abstract: The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the tenth public data release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through… ▽ More The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the tenth public data release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July. The APOGEE instrument is a near-infrared R~22,500 300-fiber spectrograph covering 1.514--1.696 microns. The APOGEE survey is studying the chemical abundances and radial velocities of roughly 100,000 red giant star candidates in the bulge, bar, disk, and halo of the Milky Way. DR10 includes 178,397 spectra of 57,454 stars, each typically observed three or more times, from APOGEE. Derived quantities from these spectra (radial velocities, effective temperatures, surface gravities, and metallicities) are also included.DR10 also roughly doubles the number of BOSS spectra over those included in the ninth data release. DR10 includes a total of 1,507,954 BOSS spectra, comprising 927,844 galaxy spectra; 182,009 quasar spectra; and 159,327 stellar spectra, selected over 6373.2 square degrees. △ Less

Submitted 17 January, 2014; v1 submitted 29 July, 2013; originally announced July 2013.

Comments: 15 figures; 1 table. Accepted to ApJS. DR10 is available at http://www.sdss3.org/dr10 v3 fixed 3 diacritic markings in the arXiv HTML listing of the author names

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological constraints from the full shape of the clustering wedges

Authors: Ariel G. Sanchez, Eyal A. Kazin, Florian Beutler, Chia-Hsun Chuang, Antonio J. Cuesta, Daniel J. Eisenstein, Marc Manera, Francesco Montesano, Bob Nichol, Nikhil Padmanabhan, Will Percival, Francisco Prada, Ashley J. Ross, David J. Schlegel, Jeremy Tinker, Rita Tojeiro, David H. Weinberg, Xiaoying Xu, J. Brinkmann, Joel R. Brownstein, Donald P. Schneider, Daniel Thomas

Abstract: We explore the cosmological implications of the clustering wedges, xi_perp(s) and xi_para(s), of the CMASS Data Release 9 (DR9) sample of the Baryon Oscillation Spectroscopic Survey (BOSS). These clustering wedges are defined by averaging the full two-dimensional correlation function, xi(mu,s), over the ranges 0<mu<0.5 and 0.5<mu<1, respectively. These measurements allow us to constrain the parame… ▽ More We explore the cosmological implications of the clustering wedges, xi_perp(s) and xi_para(s), of the CMASS Data Release 9 (DR9) sample of the Baryon Oscillation Spectroscopic Survey (BOSS). These clustering wedges are defined by averaging the full two-dimensional correlation function, xi(mu,s), over the ranges 0<mu<0.5 and 0.5<mu<1, respectively. These measurements allow us to constrain the parameter combinations D_A(z)/r_s(z_d)=9.03 +- 0.21 and cz/(r_s(z_d)H(z)) = 12.14 +- 0.43 at the mean redsfhit of the sample, z=0.57. We combine the information from the clustering wedges with recent measurements of CMB, BAO and type Ia supernovae to obtain constraints on the cosmological parameters of the standard LCDM model and a number of potential extensions. The information encoded in the clustering wedges is most useful when the dark energy equation of state is allowed to deviate from its standard LCDM value. The combination of all datasets shows no evidence of a deviation from a constant dark energy equation of state, in which case we find w_DE = -1.013 +- 0.064, in complete agreement with a cosmological constant. We explore potential deviations from general relativity by constraining the growth rate f(z)=d ln D(a)/ d ln a, in which case the combination of the CMASS clustering wedges with CMB data implies f(z=0.57)=0.719 +- 0.094, in accordance with the predictions of GR. Our results clearly illustrate the additional constraining power of anisotropic clustering measurements with respect to that of angle-averaged quantities. △ Less

Submitted 18 March, 2013; originally announced March 2013.

Comments: 24 pages, 15 figures. Submitted to MNRAS

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: weighing the neutrino mass using the galaxy power spectrum of the CMASS sample

Authors: Gong-Bo Zhao, Shun Saito, Will J. Percival, Ashley J. Ross, Francesco Montesano, Matteo Viel, Donald P. Schneider, David J. Ernst, Marc Manera, Jordi Miralda-Escude, Nicholas P. Ross, Lado Samushia, Ariel G. Sanchez, Molly E. C. Swanson, Daniel Thomas, Rita Tojeiro, Christophe Yeche, Donald G. York

Abstract: We measure the sum of the neutrino particle masses using the three-dimensional galaxy power spectrum of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 9 (DR9) CMASS galaxy sample. Combined with the cosmic microwave background (CMB), supernova (SN) and additional baryonic acoustic oscillation (BAO) data, we find upper 95 percent confidence limits of the neutrino mass… ▽ More We measure the sum of the neutrino particle masses using the three-dimensional galaxy power spectrum of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 9 (DR9) CMASS galaxy sample. Combined with the cosmic microwave background (CMB), supernova (SN) and additional baryonic acoustic oscillation (BAO) data, we find upper 95 percent confidence limits of the neutrino mass $Σm_ν<0.340$ eV within a flat $Λ$CDM background, and $Σm_ν<0.821$ eV, assuming a more general background cosmological model. The number of neutrino species is measured to be $N_{\rm eff}=4.308\pm0.794$ and $N_{\rm eff}=4.032^{+0.870}_{-0.894}$ for these two cases respectively. We study and quantify the effect of several factors on the neutrino measurements, including the galaxy power spectrum bias model, the effect of redshift-space distortion, the cutoff scale of the power spectrum, and the choice of additional data. The impact of neutrinos with unknown masses on other cosmological parameter measurements is investigated. The fractional matter density and the Hubble parameter are measured to be $Ω_M=0.2796\pm0.0097$, $H_0=69.72^{+0.90}_{-0.91}$ km/s/Mpc (flat $Λ$CDM) and $Ω_M=0.2798^{+0.0132}_{-0.0136}$, $H_0=73.78^{+3.16}_{-3.17}$ km/s/Mpc (more general background model). Based on a Chevallier-Polarski-Linder (CPL) parametrisation of the equation-of-state $w$ of dark energy, we find that $w=-1$ is consistent with observations, even allowing for neutrinos. Similarly, the curvature Ω_K and the running of the spectral index $α_s$ are both consistent with zero. The tensor-to-scaler ratio is constrained down to $r<0.198$ (95 percent CL, flat $Λ$ CDM) and $r<0.440$ (95 percent CL, more general background model). △ Less

Submitted 10 March, 2014; v1 submitted 15 November, 2012; originally announced November 2012.

Comments: 18 pages, 19 figures, 8 tables, matches the published version in MNRAS

Journal ref: MNRAS (2013) 436: 2038-2053

The Clustering of Galaxies in SDSS-III DR9 Baryon Oscillation Spectroscopic Survey: Constraints on Primordial Non-Gaussianity

Authors: Ashley J. Ross, Will J. Percival, Aurelio Carnero, Gong-bo Zhao, Marc Manera, Alvise Raccanelli, Eric Aubourg, Dmitry Bizyaev, Howard Brewington, J. Brinkmann, Joel R. Brownstein, Antonio J. Cuesta, Luiz A. N. da Costa, Daniel J. Eisenstein, Garrett Ebelke, Hong Guo, Jean-Christophe Hamilton, Mariana Vargas Magana, Elena Malanushenko, Viktor Malanushenko, Claudia Maraston, Francesco Montesano, Robert C. Nichol, Daniel Oravetz, Kaike Pan , et al. (14 additional authors not shown)

Abstract: We analyze the density field of 264,283 galaxies observed by the Sloan Digital Sky Survey (SDSS)-III Baryon Oscillation Spectroscopic Survey (BOSS) and included in the SDSS data release nine (DR9). In total, the SDSS DR9 BOSS data includes spectroscopic redshifts for over 400,000 galaxies spread over a footprint of more than 3,000 deg^2. We measure the power spectrum of these galaxies with redshif… ▽ More We analyze the density field of 264,283 galaxies observed by the Sloan Digital Sky Survey (SDSS)-III Baryon Oscillation Spectroscopic Survey (BOSS) and included in the SDSS data release nine (DR9). In total, the SDSS DR9 BOSS data includes spectroscopic redshifts for over 400,000 galaxies spread over a footprint of more than 3,000 deg^2. We measure the power spectrum of these galaxies with redshifts 0.43 < z < 0.7 in order to constrain the amount of local non-Gaussianity, f_NL,local, in the primordial density field, paying particular attention to the impact of systematic uncertainties. The BOSS galaxy density field is systematically affected by the local stellar density and this influences the ability to accurately measure f_NL,local. In the absence of any correction, we find (erroneously) that the probability that f_NL,local is greater than zero, P(f_NL,local >0), is 99.5%. After quantifying and correcting for the systematic bias and including the added uncertainty, we find -45 < f_NL,local < 195 at 95% confidence, and P(f_NL,local >0) = 91.0%. A more conservative approach assumes that we have only learned the k-dependence of the systematic bias and allows any amplitude for the systematic correction; we find that the systematic effect is not fully degenerate with that of f_NL,local, and we determine that -82 < f_NL,local < 178 (at 95% confidence) and P(f_NL,local >0) = 68%. This analysis demonstrates the importance of accounting for the impact of Galactic foregrounds on f_NL,local measurements. We outline the methods that account for these systematic biases and uncertainties. We expect our methods to yield robust constraints on f_NL,local for both our own and future large-scale-structure investigations. △ Less

Submitted 8 November, 2012; v1 submitted 7 August, 2012; originally announced August 2012.

Comments: Matches version to be published in MNRAS. While in press, we found an error that caused all of our fNL values to be off by a factor of h^2. Our conclusions (and nearly 100% of the text) are unchanged because they were all in reference to the probability of fNL > 0 and the relative effect of systematics on the recovered constraints

The Baryon Oscillation Spectroscopic Survey of SDSS-III

Authors: Kyle S. Dawson, David J. Schlegel, Christopher P. Ahn, Scott F. Anderson, Éric Aubourg, Stephen Bailey, Robert H. Barkhouser, Julian E. Bautista, Alessandra Beifiori, Andreas A. Berlind, Vaishali Bhardwaj, Dmitry Bizyaev, Cullen H. Blake, Michael R. Blanton, Michael Blomqvist, Adam S. Bolton, Arnaud Borde, Jo Bovy, W. N. Brandt, Howard Brewington, Jon Brinkmann, Peter J. Brown, Joel R. Brownstein, Kevin Bundy, N. G. Busca , et al. (140 additional authors not shown)

Abstract: The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses 1.5 million luminous galaxies as faint as i=19.9 over 10,000 square degrees to measure BAO to redshifts z<0.7. Observations of ne… ▽ More The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses 1.5 million luminous galaxies as faint as i=19.9 over 10,000 square degrees to measure BAO to redshifts z<0.7. Observations of neutral hydrogen in the Lyman alpha forest in more than 150,000 quasar spectra (g<22) will constrain BAO over the redshift range 2.15<z<3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Lyman alpha forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance D_A to an accuracy of 1.0% at redshifts z=0.3 and z=0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Lyman alpha forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D_A(z) and H^{-1}(z) parameters to an accuracy of 1.9% at z~2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS. △ Less

Submitted 7 November, 2012; v1 submitted 31 July, 2012; originally announced August 2012.

Comments: 49 pages, 16 figures, accepted by AJ

The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

Authors: SDSS-III Collaboration, :, Christopher P. Ahn, Rachael Alexandroff, Carlos Allende Prieto, Scott F. Anderson, Timothy Anderton, Brett H. Andrews, Éric Aubourg Stephen Bailey, Rory Barnes, Julian Bautista, Timothy C. Beers, Alessandra Beifiori, Andreas A. Berlind, Vaishali Bhardwaj, Dmitry Bizyaev, Cullen H. Blake, Michael R. Blanton, Michael Blomqvist, John J. Bochanski, Adam S. Bolton, Arnaud Borde, Jo Bovy, W. N. Brandt, J. Brinkmann , et al. (203 additional authors not shown)

Abstract: The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtain… ▽ More The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014. △ Less

Submitted 30 July, 2012; originally announced July 2012.

Comments: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at http://www.sdss3.org/dr9

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological implications of the large-scale two-point correlation function

Authors: Ariel G. Sanchez, C. G. Scoccola, A. J. Ross, W. Percival, M. Manera, F. Montesano, X. Mazzalay, A. J. Cuesta, D. J. Eisenstein, E. Kazin, C. K. McBride, K. Mehta, A. D. Montero-Dorta, N. Padmanabhan, F. Prada, J. A. Rubino-Martin, R. Tojeiro, X. Xu, M. Vargas Magana, E. Aubourg, N. A. Bahcall, S. Bailey, D. Bizyaev, A. S. Bolton, H. Brewington , et al. (31 additional authors not shown)

Abstract: We obtain constraints on cosmological parameters from the spherically averaged redshift-space correlation function of the CMASS Data Release 9 (DR9) sample of the Baryonic Oscillation Spectroscopic Survey (BOSS). We combine this information with additional data from recent CMB, SN and BAO measurements. Our results show no significant evidence of deviations from the standard flat-Lambda CDM model,… ▽ More We obtain constraints on cosmological parameters from the spherically averaged redshift-space correlation function of the CMASS Data Release 9 (DR9) sample of the Baryonic Oscillation Spectroscopic Survey (BOSS). We combine this information with additional data from recent CMB, SN and BAO measurements. Our results show no significant evidence of deviations from the standard flat-Lambda CDM model, whose basic parameters can be specified by Omega_m = 0.285 +- 0.009, 100 Omega_b = 4.59 +- 0.09, n_s = 0.96 +- 0.009, H_0 = 69.4 +- 0.8 km/s/Mpc and sigma_8 = 0.80 +- 0.02. The CMB+CMASS combination sets tight constraints on the curvature of the Universe, with Omega_k = -0.0043 +- 0.0049, and the tensor-to-scalar amplitude ratio, for which we find r < 0.16 at the 95 per cent confidence level (CL). These data show a clear signature of a deviation from scale-invariance also in the presence of tensor modes, with n_s <1 at the 99.7 per cent CL. We derive constraints on the fraction of massive neutrinos of f_nu < 0.049 (95 per cent CL), implying a limit of sum m_nu < 0.51 eV. We find no signature of a deviation from a cosmological constant from the combination of all datasets, with a constraint of w_DE = -1.033 +- 0.073 when this parameter is assumed time-independent, and no evidence of a departure from this value when it is allowed to evolve as w_DE(a) = w_0 + w_a (1 - a). The achieved accuracy on our cosmological constraints is a clear demonstration of the constraining power of current cosmological observations. △ Less

Submitted 13 June, 2012; v1 submitted 29 March, 2012; originally announced March 2012.

Comments: 26 pages, 15 figures. Minor changes to match version accepted by MNRAS

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: a large sample of mock galaxy catalogues

Authors: Marc Manera, Roman Scoccimarro, Will J. Percival, Lado Samushia, Cameron K. McBride, Ashley J. Ross, Ravi K. Sheth, Martin White, Beth A. Reid, Ariel G. Sánchez, Roland de Putter, Xiaoying Xu, Andreas A. Berlind, Jonathan Brinkmann, Bob Nichol, Francesco Montesano, Nikhil Padmanabhan, Ramin A. Skibba, Rita Tojeiro, Benjamin A. Weaver

Abstract: We present a fast method of producing mock galaxy catalogues that can be used to compute covariance matrices of large-scale clustering measurements and test the methods of analysis. Our method populates a 2nd-order Lagrangian Perturbation Theory (2LPT) matter field, where we calibrate masses of dark matter halos by detailed comparisons with N-body simulations. We demonstrate the clustering of halo… ▽ More We present a fast method of producing mock galaxy catalogues that can be used to compute covariance matrices of large-scale clustering measurements and test the methods of analysis. Our method populates a 2nd-order Lagrangian Perturbation Theory (2LPT) matter field, where we calibrate masses of dark matter halos by detailed comparisons with N-body simulations. We demonstrate the clustering of halos is recovered at ~10 per cent accuracy. We populate halos with mock galaxies using a Halo Occupation Distribution (HOD) prescription, which has been calibrated to reproduce the clustering measurements on scales between 30 and 80 Mpc/h. We compare the sample covariance matrix from our mocks with analytic estimates, and discuss differences. We have used this method to make catalogues corresponding to Data Release 9 of the Baryon Oscillation Spectroscopic Survey (BOSS),producing 600 mock catalogues of the "CMASS" galaxy sample. These mocks enabled detailed tests of methods and errors that formed an integral part of companion analyses of these galaxy data. △ Less

Submitted 1 April, 2012; v1 submitted 29 March, 2012; originally announced March 2012.

Comments: 21 pages, 18 figures, 2 tables. See companion papers that share the "The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey:" title. Mocks and covariance matrices will be available at http://www.marcmanera.net/mocks when the paper is accepted and DR9 released. Minor edits. Amended author's names. Submitted to MNRAS

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in the Data Release 9 Spectroscopic Galaxy Sample

Authors: Lauren Anderson, Eric Aubourg, Stephen Bailey, Dmitry Bizyaev, Michael Blanton, Adam S. Bolton, J. Brinkmann, Joel R. Brownstein, Angela Burden, Antonio J. Cuesta, Luiz N. A. da Costa, Kyle S. Dawson, Roland de Putter, Daniel J. Eisenstein, James E. Gunn, Hong Guo, Jean-Christophe Hamilton, Paul Harding, Shirley Ho, Klaus Honscheid, Eyal Kazin, D. Kirkby, Jean-Paul Kneib, Antione Labatie, Craig Loomis , et al. (51 additional authors not shown)

Abstract: We present measurements of galaxy clustering from the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky Survey III (SDSS-III). These use the Data Release 9 (DR9) CMASS sample, which contains 264,283 massive galaxies covering 3275 square degrees with an effective redshift z=0.57 and redshift range 0.43 < z < 0.7. Assuming a concordance Lambda-CDM cosmological mo… ▽ More We present measurements of galaxy clustering from the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky Survey III (SDSS-III). These use the Data Release 9 (DR9) CMASS sample, which contains 264,283 massive galaxies covering 3275 square degrees with an effective redshift z=0.57 and redshift range 0.43 < z < 0.7. Assuming a concordance Lambda-CDM cosmological model, this sample covers an effective volume of 2.2 Gpc^3, and represents the largest sample of the Universe ever surveyed at this density, n = 3 x 10^-4 h^-3 Mpc^3. We measure the angle-averaged galaxy 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 5σin both the correlation function and power spectrum. Combining with the SDSS-II Luminous Red Galaxy Sample, the detection significance increases to 6.7σ. Fitting for the position of the acoustic features measures the distance to z=0.57 relative to the sound horizon DV /rs = 13.67 +/- 0.22 at z=0.57. Assuming a fiducial sound horizon of 153.19 Mpc, which matches cosmic microwave background constraints, this corresponds to a distance DV(z=0.57) = 2094 +/- 34 Mpc. At 1.7 per cent, this is the most precise distance constraint ever obtained from a galaxy survey. We place this result alongside previous BAO measurements in a cosmological distance ladder and find excellent agreement with the current supernova measurements. We use these distance measurements to constrain various cosmological models, finding continuing support for a flat Universe with a cosmological constant. △ Less

Submitted 29 March, 2012; originally announced March 2012.

Comments: 33 pages

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Analysis of potential systematics

Authors: Ashley J. Ross, Will J. Percival, Ariel G. Sanchez, Lado Samushia, Shirley Ho, Eyal Kazin, Marc Manera, Beth Reid, Martin White, Rita Tojeiro, Cameron K. McBride, Xiaoying Xu, David A. Wake, Michael A. Strauss, Francesco Montesano, Molly E. C. Swanson, Stephen Bailey, Adam S. Bolton, Antonio Montero Dorta, Daniel J. Eisenstein, Hong Guo, Jean-Christophe Hamilton, Robert C. Nichol, Nikhil Padmanabhan, Francisco Prada , et al. (16 additional authors not shown)

Abstract: We analyze the density field of galaxies observed by the Sloan Digital Sky Survey (SDSS)-III Baryon Oscillation Spectroscopic Survey (BOSS) included in the SDSS Data Release Nine (DR9). DR9 includes spectroscopic redshifts for over 400,000 galaxies spread over a footprint of 3,275 deg^2. We identify, characterize, and mitigate the impact of sources of systematic uncertainty on large-scale clusteri… ▽ More We analyze the density field of galaxies observed by the Sloan Digital Sky Survey (SDSS)-III Baryon Oscillation Spectroscopic Survey (BOSS) included in the SDSS Data Release Nine (DR9). DR9 includes spectroscopic redshifts for over 400,000 galaxies spread over a footprint of 3,275 deg^2. We identify, characterize, and mitigate the impact of sources of systematic uncertainty on large-scale clustering measurements, both for angular moments of the redshift-space correlation function and the spherically averaged power spectrum, P(k), in order to ensure that robust cosmological constraints will be obtained from these data. A correlation between the projected density of stars and the higher redshift (0.43 < z < 0.7) galaxy sample (the `CMASS' sample) due to imaging systematics imparts a systematic error that is larger than the statistical error of the clustering measurements at scales s > 120h^-1Mpc or k < 0.01hMpc^-1. We find that these errors can be ameliorated by weighting galaxies based on their surface brightness and the local stellar density. We use mock galaxy catalogs that simulate the CMASS selection function to determine that randomly selecting galaxy redshifts in order to simulate the radial selection function of a random sample imparts the least systematic error on correlation function measurements and that this systematic error is negligible for the spherically averaged correlation function. The methods we recommend for the calculation of clustering measurements using the CMASS sample are adopted in companion papers that locate the position of the baryon acoustic oscillation feature (Anderson et al. 2012), constrain cosmological models using the full shape of the correlation function (Sanchez et al. 2012), and measure the rate of structure growth (Reid et al. 2012). (abridged) △ Less

Submitted 3 May, 2012; v1 submitted 29 March, 2012; originally announced March 2012.

Comments: Matches version accepted by MNRAS. Clarifications and references have been added. See companion papers that share the "The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey:" title

The clustering of galaxies at z~0.5 in the SDSS-III Data Release 9 BOSS-CMASS sample: a test for the LCDM cosmology

Authors: Sebastian E. Nuza, Ariel G. Sanchez, Francisco Prada, Anatoly Klypin, David J. Schlegel, Stefan Gottloeber, Antonio D. Montero-Dorta, Marc Manera, Cameron K. McBride, Ashley J. Ross, Raul Angulo, Michael Blanton, Adam Bolton, Ginevra Favole, Lado Samushia, Francesco Montesano, Will J. Percival, Nikhil Padmanabhan, Matthias Steinmetz, Jeremy Tinker, Ramin Skibba, Donald P. Schneider, Hong Guo, Idit Zehavi, Zheng Zheng , et al. (6 additional authors not shown)

Abstract: We present results on the clustering of 282,068 galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) sample of massive galaxies with redshifts 0.4<z<0.7 which is part of the Sloan Digital Sky Survey III project. Our results cover a large range of scales from ~0.5 to ~90 Mpc/h. We compare these estimates with the expectations of the flat LCDM cosmological model with parameters compatible… ▽ More We present results on the clustering of 282,068 galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) sample of massive galaxies with redshifts 0.4<z<0.7 which is part of the Sloan Digital Sky Survey III project. Our results cover a large range of scales from ~0.5 to ~90 Mpc/h. We compare these estimates with the expectations of the flat LCDM cosmological model with parameters compatible with WMAP7 data. We use the MultiDark cosmological simulation together with a simple halo abundance matching technique, to estimate galaxy correlation functions, power spectra, abundance of subhaloes and galaxy biases. We find that the LCDM model gives a reasonable description to the observed correlation functions at z~0.5, which is a remarkably good agreement considering that the model, once matched to the observed abundance of BOSS galaxies, does not have any free parameters. However, we find a deviation (>~10%) in the correlation functions for scales less than ~1 Mpc/h and ~10-40 Mpc/h. A more realistic abundance matching model and better statistics from upcoming observations are needed to clarify the situation. We also estimate that about 12% of the "galaxies" in the abundance-matched sample are satellites inhabiting central haloes with mass M>~1e14 M_sun/h. Using the MultiDark simulation we also study the real space halo bias b(r) of the matched catalogue finding that b=2.00+/-0.07 at large scales, consistent with the one obtained using the measured BOSS projected correlation function. Furthermore, the linear large-scale bias depends on the number density n of the abundance-matched sample as b=-0.048-(0.594+/-0.02)*log(n/(h/Mpc)^3). Extrapolating these results to BAO scales we measure a scale-dependent damping of the acoustic signal produced by non-linear evolution that leads to ~2-4% dips at ~3 sigma level for wavenumbers k>~0.1 h/Mpc in the linear large-scale bias. △ Less

Submitted 22 April, 2013; v1 submitted 27 February, 2012; originally announced February 2012.

Comments: Replaced to match published version. Typos corrected; 25 pages, 17 figures, 9 tables. To appear in MNRAS. Correlation functions (projected and redshift-space) and correlation matrices of CMASS presented in Appendix B. Correlation and covariance data for the combined CMASS sample can be downloaded from http://www.sdss3.org/science/boss_publications.php

Journal ref: Mon. Not. Roy. Astron. Soc., 432, 743-760, 2013

Cosmological implications from the full shape of the large-scale power spectrum of the SDSS DR7 luminous red galaxies

Authors: Francesco Montesano, Ariel G. Sanchez, Stefanie Phleps

Abstract: We obtain cosmological constraints from a measurement of the spherically averaged power spectrum (PS) of the distribution of about 90000 luminous red galaxies (LRGs) across 7646 deg2 in the Northern Galactic Cap from the DR7 of the SDSS. The errors and mode correlations are estimated thanks to the 160 LasDamas mock catalogues, created in order to simulate the same galaxies and to have the same sel… ▽ More We obtain cosmological constraints from a measurement of the spherically averaged power spectrum (PS) of the distribution of about 90000 luminous red galaxies (LRGs) across 7646 deg2 in the Northern Galactic Cap from the DR7 of the SDSS. The errors and mode correlations are estimated thanks to the 160 LasDamas mock catalogues, created in order to simulate the same galaxies and to have the same selection as the data. We apply a model, that can accurately describe the full shape of the PS with the use of a small number of free parameters. Using the LRG PS, in combination with the latest measurement of the temperature and polarisation anisotropy in the cosmic microwave background (CMB), the luminosity-distance relation from the largest available type 1a supernovae (SNIa) dataset and a precise determination of the local Hubble parameter, we obtain cosmological constraints for five different parameter spaces. When all the four experiments are combined, the flat LCDM model is characterised by Omega_M=0.259+-0.016, Omega_b=0.045+-0.001, n_s=0.963+-0.011, sigma_8=0.802+-0.021 and h=0.712+-0.014. When we consider curvature as a free parameter, we do not detect deviations from flatness: Omega_k=(1.6+-5.4)*10^{-3}, when only CMB and the LRG PS are used; the inclusion of the other two experiments do not improve this result. Considering the dark energy equation of state w_DE as time independent, we measure w_DE=-1.025+-0.065, for a flat geometry, w_DE=-0.981+-0.083 otherwise. When describing w_DE through a linear function of the scale factor, our results do not evidence any time evolution. In the next few years new experiments will allow to measure the clustering of galaxies with a precision much higher than achievable today. Models like the one used here will be a valuable tool in order to achieve the full potentials of the observations and obtain unbiased constraints on the cosmological parameters. △ Less

Submitted 9 January, 2012; v1 submitted 20 July, 2011; originally announced July 2011.

Comments: 28 pages, 26 figures. Accepted for publication in MNRAS

Journal ref: MNRAS, 2012, 421, 2656

A new model for the full shape of the large-scale power spectrum

Authors: Francesco Montesano, Ariel G. Sanchez, Stefanie Phleps

Abstract: We present a new model for the full shape of large-scale the power spectrum based on renormalized perturbation theory. To test the validity of this prescription, we compare this model against power spectra measured in a suite of 50 large volume, moderate resolution N-body simulations. Our results indicate that this simple model provides an accurate description of the full shape of the power spectr… ▽ More We present a new model for the full shape of large-scale the power spectrum based on renormalized perturbation theory. To test the validity of this prescription, we compare this model against power spectra measured in a suite of 50 large volume, moderate resolution N-body simulations. Our results indicate that this simple model provides an accurate description of the full shape of the power spectrum taking into account the effects of non-linear evolution, redshift-space distortions and halo bias for scales k < 0.15 h/Mpc, making it a valuable tool for the analysis of forthcoming galaxy surveys. Even though its application is restricted to large scales, this prescription can provide tighter constraints on the dark energy equation of state parameter w_{DE} than those obtained by modelling the baryonic acoustic oscillations signal only, where the information of the broad-band shape of the power spectrum is discarded. Our model is able to provide constraints comparable to those obtained by applying a similar model to the full shape of the correlation function, which is affected by different systematics. Hence, with accurate modelling of the power spectrum, the same cosmological information can be extracted from both statistics. △ Less

Submitted 5 July, 2010; originally announced July 2010.

Comments: Accepted for publication in MNRAS

Journal ref: MNRAS, 2010, 408, 2397-2412