Hahn CH, Blanton MR, Moustakas J, Coil AL, Cool RJ, Eisenstein DJ, Skibba RA, Wong KC, Zhu G. PRIMUS: Effects of Galaxy Environment on the Quiescent Fraction Evolution at z < 0.8. The Astrophysical Journal. 2015;806. Publisher's VersionAbstract
We investigate the effects of galaxy environment on the evolution of thequiescent fraction ({{f}Q}) from z=0.8 to 0.0 usingspectroscopic redshifts and multi-wavelength imaging data from the PRIsmMUlti-object Survey (PRIMUS) and the Sloan Digital Sky Survey (SDSS).Our stellar mass limited galaxy sample consists of ˜14,000 PRIMUSgalaxies within z = 0.2-0.8 and ˜64,000 SDSS galaxies within z= 0.05-0.12. We classify the galaxies as quiescent or star-forming(SF) based on an evolving specific star formation cut, and as low orhigh density environments based on fixed cylindrical apertureenvironment measurements on a volume-limited environment definingpopulation. For quiescent and SF galaxies in low or high densityenvironments, we examine the evolution of their stellar mass function(SMF). Then using the SMFs we compute{{f}Q}({{M}*}) and quantify its evolution withinour redshift range. We find that the quiescent fraction is higher athigher masses and in denser environments. The quiescent fraction riseswith cosmic time for all masses and environments. At a fiducial mass of{{10}10.5} {{M}}, from z˜ 0.7 to 0.1,
Bray AD, Eisenstein DJ, Skibba RA, Blanton MR, Coil AL, Cool RJ, Mendez AJ, Moustakas J, Zhu G. PRIMUS: The Effect of Physical Scale on the Luminosity Dependence of Galaxy Clustering via Cross-correlations. The Astrophysical Journal. 2015;811. Publisher's VersionAbstract
We report small-scale clustering measurements from the PRIsmMUlti-object Survey (PRIMUS) spectroscopic redshift survey as a functionof color and luminosity. We measure the real-space cross-correlationsbetween 62,106 primary galaxies with PRIMUS redshifts and a tracerpopulation of ∼545,000 photometric galaxies over redshifts from z =0.2 to z = 1. We separately fit a power-law model in redshift andluminosity to each of three independent color-selected samples ofgalaxies. We report clustering amplitudes at fiducial values of z = 0.5and L=1.5{L}*. The clustering of the red galaxies is ∼ 3times as strong as that of the blue galaxies and ∼ 1.5 as strong asthat of the green galaxies. We also find that the luminosity dependenceof the clustering is strongly dependent on physical scale, with greaterluminosity dependence being found between r=0.0625 {h}-1{Mpc} and r=0.25 {h}-1 {Mpc}, compared to the r=0.5{h}-1 {Mpc} to r=2 {h}-1 {Mpc} range. Moreover,over a range of two orders of magnitude in luminosity, a singlepower-law fit to the luminosity dependence is not sufficient to explainthe increase in clustering at both the bright and faint ends at thesmaller scales. We argue that luminosity-dependent clustering at smallscales is a necessary component of galaxy-halo occupation models forblue, star-forming galaxies as well as for red, quenched galaxies.
Azadi M, Aird J, Coil AL, Moustakas J, Mendez AJ, Blanton MR, Cool RJ, Eisenstein DJ, Wong KC, Zhu G. PRIMUS: The Relationship between Star Formation and AGN Accretion. The Astrophysical Journal. 2015;806. Publisher's VersionAbstract
We study the evidence for a connection between active galactic nuclei(AGNs) fueling and star formation by investigating the relationshipbetween the X-ray luminosities of AGNs and the star formation rates(SFRs) of their host galaxies. We identify a sample of 309 AGNs with{10}41\lt {L}X\lt {10}44 ergs-1 at 0.2\lt z\lt 1.2 in the PRIMUS redshift survey.We find AGNs in galaxies with a wide range of SFR at a givenLX. We do not find a significant correlation between SFR andthe observed instantaneous LX for star-forming AGN hostgalaxies. However, there is a weak but significant correlation betweenthe mean LX and SFR of detected AGNs in star-forminggalaxies, which likely reflects that LX varies on shortertimescales than SFR. We find no correlation between stellar mass andLX within the AGN population. Within both populations ofstar-forming and quiescent galaxies, we find a similar power-lawdistribution in the probability of hosting an AGN as a function ofspecific accretion rate. Furthermore, at a given stellar mass, we find astar-forming galaxy ˜2-3 more likely than a quiescent galaxyto host an AGN of a given specific accretion rate. The probability of agalaxy hosting an AGN is constant across the main sequence of starformation. These results indicate that there is an underlying connectionbetween star formation and the presence of AGNs, but AGNs are oftenhosted by quiescent galaxies.
Aubourg É, Bailey S, Bautista JE, Beutler F, Bhardwaj V, Bizyaev D, Blanton M, Blomqvist M, Bolton AS, Bovy J, et al. Cosmological implications of baryon acoustic oscillation measurements. Physical Review D. 2015;92. Publisher's VersionAbstract
We derive constraints on cosmological parameters and tests of darkenergy models from the combination of baryon acoustic oscillation (BAO)measurements with cosmic microwave background (CMB) data and a recentreanalysis of Type Ia supernova (SN) data. In particular, we takeadvantage of high-precision BAO measurements from galaxy clustering andthe Lyman-α forest (LyaF) in the SDSS-III Baryon OscillationSpectroscopic Survey (BOSS). Treating the BAO scale as an uncalibratedstandard ruler, BAO data alone yield a high confidence detection of darkenergy; in combination with the CMB angular acoustic scale they furtherimply a nearly flat universe. Adding the CMB-calibrated physical scaleof the sound horizon, the combination of BAO and SN data into an"inverse distance ladder" yields a measurement of H0=67.3
Delubac T, Bautista JE, Busca NG, Rich J, Kirkby D, Bailey S, Font-Ribera A, Slosar A, Lee K-G, Pieri MM, et al. Baryon acoustic oscillations in the Lyα forest of BOSS DR11 quasars. Astronomy and Astrophysics. 2015;574 :59. Publisher's VersionAbstract
We report a detection of the baryon acousticoscillation (BAO) feature inthe flux-correlation function of the Lyα forest of high-redshiftquasars with a statistical significance of five standard deviations. Thestudy uses 137 562 quasars in the redshift range 2.1 ≤ z ≤ 3.5from the data release 11 (DR11) of the Baryon Oscillation SpectroscopicSurvey (BOSS) of SDSS-III. This sample contains three times the numberof quasars used in previous studies. The measured position of the BAOpeak determines the angular distance, DA(z = 2.34) andexpansion rate, H(z = 2.34), both on a scale set by the sound horizon atthe drag epoch, rd. We find DA/rd =11.28 ± 0.65(1σ)+2.8-1.2 (2σ)and DH/rd = 9.18 ± 0.28(1σ) ±0.6(2σ) where DH = c/H. The optimal combination,~DH0.7DA0.3/rd is
Kim AG, Padmanabhan N, Aldering G, Allen SW, Baltay C, Cahn RN, D'Andrea CB, Dalal N, Dawson KS, Denney KD, et al. Distance probes of dark energy. Astroparticle Physics. 2015;63 :2-22. Publisher's VersionAbstract
This document presents the results from the Distances subgroup of theCosmic Frontier Community Planning Study (Snowmass 2013). We summarizethe current state of the field as well as future prospects andchallenges. In addition to the established probes using Type Iasupernovae and baryon acoustic oscillations, we also considerprospective methods based on clusters, active galactic nuclei,gravitational wave sirens and strong lensing time delays.
Kepler SO, Pelisoli I, Koester D, Ourique G, Kleinman SJ, Romero AD, Nitta A, Eisenstein DJ, Costa JES, Külebi B, et al. New white dwarf stars in the Sloan Digital Sky Survey Data Release 10. Monthly Notices of the Royal Astronomical Society. 2015;446 :4078-4087. Publisher's VersionAbstract
We report the discovery of 9088 new spectroscopically confirmed whitedwarfs and subdwarfs in the Sloan Digital Sky Survey Data Release 10. Weobtain Teff, log g and mass for hydrogen atmosphere whitedwarf stars (DAs) and helium atmosphere white dwarf stars (DBs), andestimate the calcium/helium abundances for the white dwarf stars withmetallic lines (DZs) and carbon/helium for carbon-dominated spectra DQs.We found 1 central star of a planetary nebula, 2 new oxygen spectra onhelium atmosphere white dwarfs, 71 DQs, 42 hot DO/PG1159s, 171 whitedwarf+main-sequence star binaries, 206 magnetic DAHs, 327continuum-dominated DCs, 397 metal-polluted white dwarfs, 450helium-dominated white dwarfs, 647 subdwarfs and 6887 newhydrogen-dominated white dwarf stars.
Slepian Z, Eisenstein DJ. On the signature of the baryon-dark matter relative velocity in the two- and three-point galaxy correlation functions. Monthly Notices of the Royal Astronomical Society. 2015;448 :9-26. Publisher's VersionAbstract
We develop a configuration-space picture of the relative velocitybetween baryons and dark matter that clearly explains how it can shiftthe baryon acoustic oscillation (BAO) scale in the galaxy-galaxycorrelation function. The shift occurs because the relative velocity isnon-zero only within the sound horizon and thus adds to the correlationfunction asymmetrically about the BAO peak. We further show that inconfiguration space the relative velocity has a localized, distinctivesignature in the three-point galaxy correlation function (3PCF). Inparticular, we find that a multipole decomposition is a favourable wayto isolate the relative velocity in the 3PCF, and that there is a strongsignature in the l = 1 multipole for triangles with two sides around theBAO scale. Finally, we investigate a further compression of the 3PCF toa function of only one triangle side that preserves the localized natureof the relative velocity signature while also nicely separating linearfrom non-linear bias. We expect that this scheme will substantiallylessen the computational burden of finding the relative velocity in the3PCF. The relative velocity's 3PCF signature can be used to correct theshift induced in the galaxy-galaxy correlation function so that nosystematic error due to this effect is introduced into the BAO as usedfor precision cosmology.
Shen Y, Brandt WN, Dawson KS, Hall PB, McGreer ID, Anderson SF, Chen Y, Denney KD, Eftekharzadeh S, Fan X, et al. The Sloan Digital Sky Survey Reverberation Mapping Project: Technical Overview. The Astrophysical Journal Supplement Series. 2015;216 :4. Publisher's VersionAbstract
The Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project isa dedicated multi-object RM experiment that has spectroscopicallymonitored a sample of 849 broad-line quasars in a single 7deg2 field with the SDSS-III Baryon Oscillation SpectroscopicSurvey spectrograph. The RM quasar sample is flux-limited to ipsf = 21.7 mag, and covers a redshift range of 0.1 < z< 4.5 without any other cuts on quasar properties. Opticalspectroscopy was performed during 2014 January-July dark/gray time, withan average cadence of ~4 days, totaling more than 30 epochs. Supportingphotometric monitoring in the g and i bands was conducted at multiplefacilities including the Canada-France-Hawaii Telescope (CFHT) and theSteward Observatory Bok telescope in 2014, with a cadence of ~2 days andcovering all lunar phases. The RM field (R.A., decl. = 14:14:49.00,+53:05:00.0) lies within the CFHT-LS W3 field, and coincides with thePan-STARRS 1 (PS1) Medium Deep Field MD07, with three prior years ofmulti-band PS1 light curves. The SDSS-RM six month baseline program aimsto detect time lags between the quasar continuum and broad line region(BLR) variability on timescales of up to several months (in the observed
Agarwal N, Ho S, Myers AD, Seo H-J, Ross AJ, Bahcall N, Brinkmann J, Eisenstein DJ, Muna D, Palanque-Delabrouille N, et al. Characterizing unknown systematics in large scale structure surveys. Journal of Cosmology and Astro-Particle Physics. 2014;04 :007. Publisher's VersionAbstract
Photometric large scale structure (LSS) surveys probe the largestvolumes in the Universe, but are inevitably limited by systematicuncertainties. Imperfect photometric calibration leads to biases in ourmeasurements of the density fields of LSS tracers such as galaxies andquasars, and as a result in cosmological parameter estimation. Earlierstudies have proposed using cross-correlations between differentredshift slices or cross-correlations between different surveys toreduce the effects of such systematics. In this paper we develop amethod to characterize unknown systematics. We demonstrate that while wedo not have sufficient information to correct for unknown systematics inthe data, we can obtain an estimate of their magnitude. We define aparameter to estimate contamination from unknown systematics usingcross-correlations between different redshift slices and proposediscarding bins in the angular power spectrum that lie outside a certaincontamination tolerance level. We show that this method improvesestimates of the bias using simulated data and further apply it tophotometric luminous red galaxies in the Sloan Digital Sky Survey as acase study.
Percival WJ, Ross AJ, Sánchez AG, Samushia L, Burden A, Crittenden R, Cuesta AJ, Magana MV, Manera M, Beutler F, et al. The clustering of Galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: including covariance matrix errors. Monthly Notices of the Royal Astronomical Society. 2014;439 :2531-2541. Publisher's VersionAbstract
We present improved methodology for including covariance matrices in theerror budget of Baryon Oscillation Spectroscopic Survey (BOSS) galaxyclustering measurements, revisiting Data Release 9 (DR9) analyses, anddescribing a method that is used in DR10/11 analyses presented incompanion papers. The precise analysis method adopted is becomingincreasingly important, due to the precision that BOSS can now reach:even using as many as 600 mock catalogues to estimate covariance oftwo-point clustering measurements can still lead to an increase in theerrors of ˜20 per cent, depending on how the cosmologicalparameters of interest are measured. In this paper, we extend previouswork on this contribution to the error budget, deriving formulae forerrors measured by integrating over the likelihood, and to thedistribution of recovered best-fitting parameters fitting thesimulations also used to estimate the covariance matrix. Both aresituations that previous analyses of BOSS have considered. We apply theformulae derived to baryon acoustic oscillation (BAO) and redshift-spacedistortion (RSD) measurements from BOSS in our companion papers. Tofurther aid these analyses, we consider the optimum number of bins touse for two-point measurements using the monopole power spectrum orcorrelation function for BAO, and the monopole and quadrupole moments ofthe correlation function for anisotropic-BAO and RSD measurements.
Anderson L, Aubourg E, Bailey S, Beutler F, Bolton AS, Brinkmann J, Brownstein JR, Chuang C-H, Cuesta AJ, Dawson KS, et al. The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: measuring DA and H at z = 0.57 from the baryon acoustic peak in the Data Release 9 spectroscopic Galaxy sample. Monthly Notices of the Royal Astronomical Society. 2014;439 :83-101. Publisher's VersionAbstract
We present measurements of the angular diameter distance to and Hubbleparameter at z = 0.57 from the measurement of the baryon acoustic peakin the correlation of galaxies from the Sloan Digital Sky Survey IIIBaryon Oscillation Spectroscopic Survey. Our analysis is based on asample from Data Release 9 of 264 283 galaxies over 3275 square degreesin the redshift range 0.43 < z < 0.70. We use two differentmethods to provide robust measurement of the acoustic peak positionacross and along the line of sight in order to measure the cosmologicaldistance scale. We find DA(0.57) = 1408 ± 45 Mpc andH(0.57) = 92.9 ± 7.8 km s-1 Mpc-1 for ourfiducial value of the sound horizon. These results from the anisotropicfitting are fully consistent with the analysis of the sphericallyaveraged acoustic peak position presented in Anderson et al. Ourdistance measurements are a close match to the predictions of thestandard cosmological model featuring a cosmological constant and zerospatial curvature.
Samushia L, Reid BA, White M, Percival WJ, Cuesta AJ, Zhao G-bo, Ross AJ, Manera M, Aubourg É, Beutler F, et al. The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: measuring growth rate and geometry with anisotropic clustering. Monthly Notices of the Royal Astronomical Society. 2014;439 :3504-3519. Publisher's VersionAbstract
We use the observed anisotropic clustering of galaxies in the BaryonOscillation Spectroscopic Survey Data Release 11 CMASS sample to measurethe linear growth rate of structure, the Hubble expansion rate and thecomoving distance scale. Our sample covers 8498 deg2 andencloses an effective volume of 6 Gpc3 at an effectiveredshift of bar{z} = 0.57. We find fσ8 = 0.441 ±0.044, H = 93.1 ± 3.0 km s-1 Mpc-1 andDA = 1380 ± 23 Mpc when fitting the growth andexpansion rate simultaneously. When we fix the background expansion tothe one predicted by spatially flat Λ cold dark matter(ΛCDM) model in agreement with recent Planck results, we findfσ8 = 0.447 ± 0.028 (6 per cent accuracy). Whileour measurements are generally consistent with the predictions ofΛCDM and general relativity, they mildly favour models in whichthe strength of gravitational interactions is weaker than what ispredicted by general relativity. Combining our measurements with recentcosmic microwave background data results in tight constraints on basiccosmological parameters and deviations from the standard cosmologicalmodel. Separately varying these parameters, we find w = -0.983 ±0.075 (8 per cent accuracy) and γ = 0.69 ± 0.11 (16 percent accuracy) for the effective equation of state of dark energy andthe growth rate index, respectively. Both constraints are in goodagreement with the standard model values of w = -1 and γ = 0.554.
Skibba RA, Smith SMM, Coil AL, Moustakas J, Aird J, Blanton MR, Bray AD, Cool RJ, Eisenstein DJ, Mendez AJ, et al. PRIMUS: Galaxy Clustering as a Function of Luminosity and Color at 0.2 < z < 1. The Astrophysical Journal. 2014;784 :128. Publisher's VersionAbstract
We present measurements of the luminosity and color-dependence of galaxyclustering at 0.2 < z < 1.0 in the Prism Multi-object Survey. Wequantify the clustering with the redshift-space and projected two-pointcorrelation functions, ξ(rp , π) and wp(rp ), using volume-limited samples constructed from a parentsample of over ~130, 000 galaxies with robust redshifts in sevenindependent fields covering 9 deg2 of sky. We quantify howthe scale-dependent clustering amplitude increases with increasingluminosity and redder color, with relatively small errors over largevolumes. We find that red galaxies have stronger small-scale (0.1 Mpc h-1 < rp < 1 Mpc h -1)clustering and steeper correlation functions compared to blue galaxies,as well as a strong color dependent clustering within the red sequencealone. We interpret our measured clustering trends in terms of galaxybias and obtain values of b gal ≈ 0.9-2.5, quantifying howgalaxies are biased tracers of dark matter depending on their luminosityand color. We also interpret the color dependence with mock catalogs,and find that the clustering of blue galaxies is nearly constant withcolor, while redder galaxies have stronger clustering in the one-haloterm due to a higher satellite galaxy fraction. In addition, we measurethe evolution of the clustering strength and bias, and we do not detectstatistically significant departures from passive evolution. We arguethat the luminosity- and color-environment (or halo mass) relations ofgalaxies have not significantly evolved since z ~ 1. Finally, usingjackknife subsampling methods, we find that sampling fluctuations areimportant and that the COSMOS field is generally an outlier, due tohaving more overdense structures than other fields; we find that "cosmicvariance" can be a significant source of uncertainty for high-redshiftclustering measurements.
Font-Ribera A, Kirkby D, Busca N, Miralda-Escudé J, Ross NP, Slosar A, Rich J, Aubourg É, Bailey S, Bhardwaj V, et al. Quasar-Lyman α forest cross-correlation from BOSS DR11: Baryon Acoustic Oscillations. Journal of Cosmology and Astro-Particle Physics. 2014;05 :027. Publisher's VersionAbstract
We measure the large-scale cross-correlation of quasars with theLyα forest absorption, using over 164,000 quasars from DataRelease 11 of the SDSS-III Baryon Oscillation Spectroscopic Survey. Weextend the previous study of roughly 60,000 quasars from Data Release 9to larger separations, allowing a measurement of the Baryonic AcousticOscillation (BAO) scale along the line of sight c/(H(z =2.36)rs) = 9.0±0.3 and across the line of sightDA(z = 2.36)/rs = 10.8±0.4, consistent withCMB and other BAO data. Using the best fit value of the sound horizonfrom Planck data (rs = 147.49 Mpc), we can translate theseresults to a measurement of the Hubble parameter of H(z = 2.36) =226±8 km s-1 Mpc-1 and of theangular diameter distance of DA(z = 2.36) = 1590±60Mpc. The measured cross-correlation function and an update of the codeto fit the BAO scale (baofit) are made publicly available.
Ahn CP, Alexandroff R, Allende Prieto C, Anders F, Anderson SF, Anderton T, Andrews BH, Aubourg É, Bailey S, Bastien FA, et al. The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment. The Astrophysical Journal Supplement Series. 2014;211 :17. Publisher's VersionAbstract
The Sloan Digital Sky Survey (SDSS) has been in operation since 2000April. This paper presents the Tenth Public Data Release (DR10) from itscurrent incarnation, SDSS-III. This data release includes the firstspectroscopic data from the Apache Point Observatory Galaxy EvolutionExperiment (APOGEE), along with spectroscopic data from the BaryonOscillation Spectroscopic Survey (BOSS) taken through 2012 July. TheAPOGEE instrument is a near-infrared R ~ 22,500 300 fiber spectrographcovering 1.514-1.696 μm. The APOGEE survey is studying the chemicalabundances and radial velocities of roughly 100,000 red giant starcandidates in the bulge, bar, disk, and halo of the Milky Way. DR10includes 178,397 spectra of 57,454 stars, each typically observed threeor more times, from APOGEE. Derived quantities from these spectra(radial velocities, effective temperatures, surface gravities, andmetallicities) are also included. DR10 also roughly doubles the numberof BOSS spectra over those included in the Ninth Data Release. DR10includes a total of 1,507,954 BOSS spectra comprising 927,844 galaxyspectra, 182,009 quasar spectra, and 159,327 stellar spectra selectedover 6373.2 deg2.
Beutler F, Saito S, Seo H-J, Brinkmann J, Dawson KS, Eisenstein DJ, Font-Ribera A, Ho S, McBride CK, Montesano F, et al. The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: testing gravity with redshift space distortions using the power spectrum multipoles. Monthly Notices of the Royal Astronomical Society. 2014;443 :1065-1089. Publisher's VersionAbstract
We analyse the anisotropic clustering of the Baryon OscillationSpectroscopic Survey (BOSS) CMASS Data Release 11 (DR11) sample, whichconsists of 690 827 galaxies in the redshift range 0.43 < z < 0.7and has a sky coverage of 8498 deg2. We perform our analysisin Fourier space using a power spectrum estimator suggested by Yamamotoet al. We measure the multipole power spectra in a self-consistentmanner for the first time in the sense that we provide a proper way totreat the survey window function and the integral constraint, withoutthe commonly used assumption of an isotropic power spectrum and withoutthe need to split the survey into subregions. The main cosmologicalsignals exploited in our analysis are the baryon acoustic oscillationsand the signal of redshift space distortions, both of which aredistorted by the Alcock-Paczynski effect. Together, these signals allowus to constrain the distance ratioDV(zeff)/rs(zd) = 13.89± 0.18, the Alcock-Paczynski parameterFAP(zeff) = 0.679 ± 0.031 and the growthrate of structure f(zeff8(zeff) = 0.419 ±0.044 at the effective redshift zeff = 0.57. We emphasizethat our constraints are robust against possible systematicuncertainties. In order to ensure this, we perform a detailedsystematics study against CMASS mock galaxy catalogues and N-bodysimulations. We find that such systematics will lead to 3.1 per centuncertainty for fσ8 if we limit our fitting range to k= 0.01-0.20 h Mpc-1, where the statistical uncertainty isexpected to be three times larger. We did not find significantsystematic uncertainties for DV/rs orFAP. Combining our data set with Planck to test GeneralRelativity (GR) through the simple γ-parametrization, where thegrowth rate is given by f(z) = Ω ^{γ }_m(z), reveals a˜2σ tension between the data and the prediction by GR. Thetension between our result and GR can be traced back to a tension in theclustering amplitude σ8 between CMASS and Planck.
Sánchez AG, Montesano F, Kazin EA, Aubourg E, Beutler F, Brinkmann J, Brownstein JR, Cuesta AJ, Dawson KS, Eisenstein DJ, et al. 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. Monthly Notices of the Royal Astronomical Society. 2014;440 :2692-2713. Publisher's VersionAbstract
We explore the cosmological implications of the angle-averagedcorrelation function, ξ(s), and the clustering wedges,ξ(s) and ξ(s), of the LOWZ andCMASS galaxy samples from Data Releases 10 and 11 of the Sloan DigitalSky Survey III (SDSS-III) Baryon Oscillation Spectroscopic Survey. Ourresults show no significant evidence for a deviation from the standardΛ cold dark matter model. The combination of the information fromour clustering measurements with recent data from the cosmic microwavebackground is sufficient to constrain the curvature of the Universe toΩk = 0.0010 ± 0.0029, the total neutrino mass to∑mν < 0.23 eV (95 per cent confidence level), theeffective number of relativistic species to Neff = 3.31± 0.27 and the dark energy equation of state to wDE =-1.051 ± 0.076. These limits are further improved by addinginformation from Type Ia supernovae and baryon acoustic oscillationsfrom other samples. In particular, this data set combination iscompletely consistent with a time-independent dark energy equation ofstate, in which case we find wDE = -1.024 ± 0.052. Weexplore the constraints on the growth rate of cosmic structures assumingf(z) = Ωm(z)γ and obtain γ =0.69 ± 0.15, consistent with the predictions of generalrelativity of γ = 0.55.
Anderson L, Aubourg É, Bailey S, Beutler F, Bhardwaj V, Blanton M, Bolton AS, Brinkmann J, Brownstein JR, Burden A, et al. The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: baryon acoustic oscillations in the Data Releases 10 and 11 Galaxy samples. Monthly Notices of the Royal Astronomical Society. 2014;441 :24-62. Publisher's VersionAbstract
We present a one per cent measurement of the cosmic distance scale fromthe detections of the baryon acoustic oscillations (BAO) in theclustering of galaxies from the Baryon Oscillation Spectroscopic Survey,which is part of the Sloan Digital Sky Survey III. Our results come fromthe Data Release 11 (DR11) sample, containing nearly one milliongalaxies and covering approximately 8500 square degrees and the redshiftrange 0.2 < z < 0.7. We also compare these results with those fromthe publicly released DR9 and DR10 samples. Assuming a concordanceΛ cold dark matter (ΛCDM) cosmological model, the DR11sample covers a volume of 13 Gpc3 and is the largest regionof the Universe ever surveyed at this density. We measure thecorrelation function and power spectrum, including density-fieldreconstruction of the BAO feature. The acoustic features are detected ata significance of over 7σ in both the correlation function andpower spectrum. Fitting for the position of the acoustic featuresmeasures the distance relative to the sound horizon at the drag epoch,rd, which has a value of rd,fid = 149.28 Mpc inour fiducial cosmology. We find DV = (1264 ± 25Mpc)(rd/rd,fid) at z = 0.32 and DV =(2056 ± 20 Mpc)(rd/rd,fid) at z = 0.57. At1.0 per cent, this latter measure is the most precise distanceconstraint ever obtained from a galaxy survey. Separating the clusteringalong and transverse to the line of sight yields measurements at z =0.57 of DA = (1421 ± 20Mpc)(rd/rd,fid) and H = (96.8 ± 3.4 kms-1 Mpc-1)(rd,fid/rd). Ourmeasurements of the distance scale are in good agreement with previousBAO measurements and with the predictions from cosmic microwavebackground data for a spatially flat CDM model with a cosmologicalconstant.
Guo H, Zheng Z, Zehavi I, Xu H, Eisenstein DJ, Weinberg DH, Bahcall NA, Berlind AA, Comparat J, McBride CK, et al. The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: modelling of the luminosity and colour dependence in the Data Release 10. Monthly Notices of the Royal Astronomical Society. 2014;441 :2398-2413. Publisher's VersionAbstract
We investigate the luminosity and colour dependence of clustering ofCMASS galaxies in the Sloan Digital Sky Survey-III Baryon OscillationSpectroscopic Survey Data Release 10, focusing on projected correlationfunctions of well-defined samples extracted from the full catalogue of˜540 000 galaxies at z ˜ 0.5 covering about 6500deg2. The halo occupation distribution framework is adoptedto model the measurements on small and intermediate scales (from 0.02 to60 h-1 Mpc), infer the connection of galaxies to dark matterhaloes and interpret the observed trends. We find that luminous redgalaxies in CMASS reside in massive haloes of mass M ˜1013-1014 h-1 M andmore luminous galaxies are more clustered and hosted by more massivehaloes. The strong small-scale clustering requires a fraction of thesegalaxies to be satellites in massive haloes, with the fraction at thelevel of 5-8 per cent and decreasing with luminosity. The characteristicmass of a halo hosting on average one satellite galaxy above aluminosity threshold is about a factor of 8.7 larger than that of a halohosting a central galaxy above the same threshold. At a fixedluminosity, progressively redder galaxies are more strongly clustered onsmall scales, which can be explained by having a larger fraction ofthese galaxies in the form of satellites in massive haloes. Ourclustering measurements on scales below 0.4 h-1 Mpc allow usto study the small-scale spatial distribution of satellites insidehaloes. While the clustering of luminosity-threshold samples can be welldescribed by a Navarro-Frenk-White profile, that of the reddest galaxiesprefers a steeper or more concentrated profile. Finally, we also usegalaxy samples of constant number density at different redshifts tostudy the evolution of luminous red galaxies, and find the clustering tobe consistent with passive evolution in the redshift range of 0.5 ≲z ≲ 0.6.