The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has beenin operation since 2014 July. This paper describes the second datarelease from this phase, and the 14th from SDSS overall (making thisData Release Fourteen or DR14). This release makes the data taken bySDSS-IV in its first two years of operation (2014-2016 July)public. Like all previous SDSS releases, DR14 is cumulative, includingthe most recent reductions and calibrations of all data taken by SDSSsince the first phase began operations in 2000. New in DR14 is the firstpublic release of data from the extended Baryon OscillationSpectroscopic Survey; the first data from the second phase of the ApachePoint Observatory (APO) Galactic Evolution Experiment (APOGEE-2),including stellar parameter estimates from an innovative data-drivenmachine-learning algorithm known as “The Cannon” and almosttwice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA)survey as were in the previous release (N = 2812 in total). This paperdescribes the location and format of the publicly available data fromthe SDSS-IV surveys. We provide references to the important technicalpapers describing how these data have been taken (both targeting andobservation details) and processed for scientific use. The SDSS web site(www.sdss.org) has been updated forthis release and provides links to data downloads, as well as tutorialsand examples of data use. SDSS-IV is planning to continue to collectastronomical data until 2020 and will be followed by SDSS-V.

We present an iterative method to reconstruct the linear-theory initialconditions from the late-time cosmological matter density field, withthe intent of improving the recovery of the cosmic distance scale fromthe baryon acoustic oscillations. We present tests using the dark matterdensity field in both real and redshift space generated from an N-bodysimulation. In redshift space at z = 0.5, we find that the reconstructeddisplacement field using our iterative method are more than 80 per centcorrelated with the true displacement field of the dark matter particleson scales k < 0.10 h Mpc^-1. Furthermore, we show that thetwo-point correlation function of our reconstructed density fieldmatches that of the initial density field substantially better,especially on small scales (<40 h^-1 Mpc). Ourredshift-space results are improved if we use an anisotropic smoothingso as to account for the reduced small-scale information along the lineof sight in redshift space.

We present an original phenomenological model to describe the evolutionof galaxy number counts, morphologies, and spectral energy distributionsacross a wide range of redshifts (0.2< z< 15) and stellar masses[{log}(M/{M}_⊙ )≥slant 6]. Our model follows observedmass and luminosity functions of both star-forming and quiescentgalaxies, and reproduces the redshift evolution of colors, sizes, starformation, and chemical properties of the observed galaxy population.Unlike other existing approaches, our model includes a self-consistenttreatment of stellar and photoionized gas emission and dust attenuationbased on the BEAGLE tool. The mock galaxy catalogs generated with ournew model can be used to simulate and optimize extragalactic surveyswith future facilities such as the James Webb Space Telescope (JWST),and to enable critical assessments of analysis procedures,interpretation tools, and measurement systematics for both photometricand spectroscopic data. As a first application of this work, we makepredictions for the upcoming JWST Advanced Deep Extragalactic Survey(JADES), a joint program of the JWST/NIRCam and NIRSpec Guaranteed TimeObservations teams. We show that JADES will detect, with NIRCam imaging,1000s of galaxies at z ≳ 6, and 10s at z ≳ 10 at{m}_{AB}≲ 30 (5σ) within the 236 arcmin²of the survey. The JADES data will enable accurate constraints on theevolution of the UV luminosity function at z > 8, and resolve thecurrent debate about the rate of evolution of galaxies at z ≳ 8.Ready-to-use mock catalogs and software to generate new realizations arepublicly available as the JAdes extraGalactic Ultradeep ArtificialRealizations (JAGUAR) package.

The Dark Energy Spectroscopic Instrument (DESI) is under construction tomeasure the expansion history of the Universe using the Baryon AcousticOscillation technique. The spectra of 35 million galaxies and quasarsover 14000 square degrees will be measured during the life of theexperiment. A new prime focus corrector for the KPNO Mayall telescopewill deliver light to 5000 fiber optic positioners. The fibers in turnfeed ten broad-band spectrographs. We present an overview of theinstrumentation, the main technical requirements and challenges, and thecurrent status of the project.

We present an algorithm enabling computation of the anisotropicredshift-space galaxy three-point correlation function (3PCF) scaling asN², with N the number of galaxies. Our previous work showedhow to compute the isotropic 3PCF with this scaling by expanding theradially binned density field around each galaxy in the survey intospherical harmonics and combining these coefficients to form multipolemoments. The N² scaling occurred because this approach neverexplicitly required the relative angle between a galaxy pair about theprimary galaxy. Here, we generalize this work, demonstrating that in thepresence of azimuthally symmetric anisotropy produced by redshift-spacedistortions (RSD), the 3PCF can be described by two triangle sidelengths, two independent total angular momenta, and a spin. This basisfor the anisotropic 3PCF allows its computation with negligibleadditional work over the isotropic 3PCF. We also present the covariancematrix of the anisotropic 3PCF measured in this basis. Our algorithmtracks the full 5D redshift-space 3PCF, uses an accurate line of sightto each triplet, is exact in angle, and easily handles edge correction.It will enable use of the anisotropic large-scale 3PCF as a probe of RSDin current and upcoming large-scale redshift surveys.

We probe the higher-order galaxy clustering in the final data release(DR12) of the Sloan Digital Sky Survey using germ-grain MinkowskiFunctionals (MFs). Our data selection contains 979,430 BOSS galaxiesfrom both the northern and southern galactic caps over the redshiftrange 0.2 - 0.6. We extract the higher-order parts of the MFs and finddeviations from the case without higher order MFs with chi-squaredvalues of order 1000 for 24 degrees of freedom across the entire dataselection. We show the MFs to be sensitive to contributions up to thefive-point correlation function across the entire data selection. Wemeasure significant redshift evolution in the higher-order functionalsfor the first time, with a percentage growth between redshift bins of

We explore the connection between the UV luminosity functions (LFs) ofhigh-z galaxies and the distribution of stellar masses and starformation histories (SFHs) in their host dark matter halos. We provide abaseline for a redshift-independent star formation efficiency model towhich observations and models can be compared. Our model assigns a starformation rate (SFR) to each dark matter halo based on the growth rateof the halo and a redshift-independent star formation efficiency. Thedark matter halo accretion rate is obtained from a high-resolutionN-body simulation in order to capture the stochasticity in accretionhistories and to obtain spatial information for the distribution ofgalaxies. The halo mass dependence of the star formation efficiency iscalibrated at z = 4 by requiring a match to the observed UV LF at thisredshift. The model then correctly predicts the observed UV LF at z =5–10. We present predictions for the UV luminosity and stellarmass functions, JWST number counts, and SFHs. In particular, we find astellar-to-halo mass relation at z = 4–10 that scales with halomass at M _h < 10¹¹ M _⊙ as M_⋆ ∝ M _h ², with anormalization that is higher than the relation inferred at z = 0. Theaverage SFRs increase as a function of time to z = 4, although there is

We present a color-based method for identifying red giants based on thePan-STARRS grz and WISE W1 and W2 photometry. We utilize a subsample ofbright stars with precise parallaxes from Gaia’s second datarelease (DR2) to verify that the color-based selection reliablyseparates dwarfs from giants. The selection is conservative in the sense

We analyse the baryon acoustic oscillation (BAO) signal of the finalBaryon Oscillation Spectroscopic Survey (BOSS) data release (DR12). Ouranalysis is performed in the Fourier space, using the power spectrummonopole and quadrupole. The data set includes 1198 006 galaxies overthe redshift range 0.2 < z < 0.75. We divide this data set intothree (overlapping) redshift bins with the effective redshiftsz_eff = 0.38, 0.51 and 0.61. We demonstrate the reliability ofour analysis pipeline using N-body simulations as well as ˜1000MultiDark-Patchy mock catalogues that mimic the BOSS-DR12 targetselection. We apply density field reconstruction to enhance the BAOsignal-to-noise ratio. By including the power spectrum quadrupole we canseparate the line of sight and angular modes, which allows us toconstrain the angular diameter distance D_A(z) and the Hubbleparameter H(z) separately. We obtain two independent 1.6 and 1.5 percent constraints on D_A(z) and 2.9 and 2.3 per centconstraints on H(z) for the low (z_eff = 0.38) and high(z_eff = 0.61) redshift bin, respectively. We obtain twoindependent 1 and 0.9 per cent constraints on the angular averageddistance D_V(z), when ignoring the Alcock-Paczynski effect.The detection significance of the BAO signal is of the order of 8σ(post-reconstruction) for each of the three redshift bins. Our resultsare in good agreement with the Planck prediction within Λ colddark matter. This paper is part of a set that analyses the final galaxyclustering data set from BOSS. The measurements and likelihoodspresented here are combined with others in Alam et al. to produce thefinal cosmological constraints from BOSS.

We present a measurement of the linear growth rate of structure, f, fromthe Sloan Digital Sky Survey III (SDSS-III) Baryon OscillationSpectroscopic Survey (BOSS) Data Release 12 (DR12) using convolutionLagrangian perturbation theory (CLPT) with Gaussian streaming redshiftspace distortions (GSRSD) to model the two-point statistics of BOSSgalaxies in DR12. The BOSS-DR12 data set includes 1198 006 massivegalaxies spread over the redshift range 0.2 < z < 0.75. Thesegalaxy samples are categorized in three redshift bins. Using CLPT-GSRSDin our analysis of the combined sample of the three redshift bins, wereport measurements of fσ₈ for the three redshift bins.We find fσ₈ = 0.430 ± 0.054 at z_eff =0.38, fσ₈ = 0.452 ± 0.057 at z_eff =0.51 and fσ₈ = 0.457 ± 0.052 at z_eff= 0.61. Our results are consistent with the predictions of PlanckΛ cold dark matter-general relativity. Our constraints on thegrowth rates of structure in the Universe at different redshifts serveas a useful probe, which can help distinguish between a model of theUniverse based on dark energy and models based on modified theories ofgravity. This paper is part of a set that analyses the final galaxyclustering data set from BOSS. The measurements and likelihoodspresented here are combined with others in Alam et al., to produce thefinal cosmological constraints from BOSS.

We extract cosmological information from the anisotropic power-spectrummeasurements from the recently completed Baryon OscillationSpectroscopic Survey (BOSS), extending the concept of clustering wedgesto Fourier space. Making use of new fast-Fourier-transform-basedestimators, we measure the power-spectrum clustering wedges of the BOSSsample by filtering out the information of Legendre multipoles ℓ> 4. Our modelling of these measurements is based on novel approachesto describe non-linear evolution, bias and redshift-space distortions,which we test using synthetic catalogues based on large-volume N-bodysimulations. We are able to include smaller scales than in previousanalyses, resulting in tighter cosmological constraints. Using threeoverlapping redshift bins, we measure the angular-diameter distance, theHubble parameter and the cosmic growth rate, and explore thecosmological implications of our full-shape clustering measurements incombination with cosmic microwave background and Type Ia supernova data.Assuming a Λ cold dark matter (ΛCDM) cosmology, weconstrain 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 of 68 percent. We also allow for non-standard dark energy models andmodifications of the growth rate, finding good agreement with theΛCDM paradigm. For example, we constrain the equation-of-stateparameter to w = -1.019_{-0.039}^{+0.048}. This paper is part of a setthat analyses the final galaxy-clustering data set from BOSS. Themeasurements and likelihoods presented here are combined with others inAlam et al. to produce the final cosmological constraints from BOSS.

We present baryon acoustic oscillation (BAO) scale measurementsdetermined from the clustering of 1.2 million massive galaxies withredshifts 0.2 < z < 0.75 distributed over 9300 deg², asquantified by their redshift-space correlation function. In order tofacilitate these measurements, we define, describe, and motivate theselection function for galaxies in the final data release (DR12) of theSDSS III Baryon Oscillation Spectroscopic Survey (BOSS). This includesthe observational footprint, masks for image quality and Galacticextinction, and weights to account for density relationships intrinsicto the imaging and spectroscopic portions of the survey. We simulate theobserved systematic trends in mock galaxy samples and demonstrate thatthey impart no bias on BAO scale measurements and have a minor impact onthe recovered statistical uncertainty. We measure transverse and radialBAO distance measurements in 0.2 < z < 0.5, 0.5 < z < 0.75,and (overlapping) 0.4 < z < 0.6 redshift bins. In each redshiftbin, we obtain a precision that is 2.7 per cent or better on the radialdistance and 1.6 per cent or better on the transverse distance. Thecombination of the redshift bins represents 1.8 per cent precision onthe radial distance and 1.1 per cent precision on the transversedistance. This paper is part of a set that analyses the final galaxyclustering data set from BOSS. The measurements and likelihoodspresented here are combined with others in Alam et al. to produce thefinal cosmological constraints from BOSS.

We develop a new computationally efficient methodology calleddouble-probe analysis with the aim of minimizing informative priors(those coming from extra probes) in the estimation of cosmologicalparameters. Using our new methodology, we extract the dark energymodel-independent cosmological constraints from the joint data sets ofthe Baryon Oscillation Spectroscopic Survey (BOSS) galaxy sample andPlanck cosmic microwave background (CMB) measurements. We measure themean values and covariance matrix of {R, l_a,Ω_bh², n_s, log(A_s),Ω_k, H(z), D_A(z),f(z)σ₈(z)}, which give an efficient summary of thePlanck data and two-point statistics from the BOSS galaxy sample. TheCMB shift parameters are R=√{Ω _m H_0^2} r(z_*) andl_a = πr(z_*)/r_s(z_*), wherez_* is the redshift at the last scattering surface, andr(z_*) and r_s(z_*) denote our comovingdistance to the z_* and sound horizon at z_*,respectively; Ω_b is the baryon fraction at z = 0. Thisapproximate methodology guarantees that we will not need to putinformative priors on the cosmological parameters that galaxy clusteringis unable to constrain, I.e. Ω_bh² andn_s. The main advantage is that the computational timerequired for extracting these parameters is decreased by a factor of 60with respect to exact full-likelihood analyses. The results obtainedshow no tension with the flat Λ cold dark matter (ΛCDM)cosmological paradigm. By comparing with the full-likelihood exactanalysis with fixed dark energy models, on one hand we demonstrate thatthe double-probe method provides robust cosmological parameterconstraints that can be conveniently used to study dark energy models,and on the other hand we provide a reliable set of measurements assumingdark energy models to be used, for example, in distance estimations. Weextend our study to measure the sum of the neutrino mass using differentmethodologies, including double-probe analysis (introduced in thisstudy), full-likelihood analysis and single-probe analysis. Fromfull-likelihood analysis, we obtain Σm_ν < 0.12(68 per cent), assuming ΛCDM and Σm_ν <0.20 (68 per cent) assuming owCDM. We also find that there is degeneracybetween observational systematics and neutrino masses, which suggeststhat one should take great care when estimating these parameters in thecase of not having control over the systematics of a given sample.

The cosmological information contained in anisotropic galaxy clusteringmeasurements can often be compressed into a small number of parameterswhose posterior distribution is well described by a Gaussian. We presenta general methodology to combine these estimates into a single set ofconsensus constraints that encode the total information of theindividual measurements, taking into account the full covariance betweenthe different methods. We illustrate this technique by applying it tocombine the results obtained from different clustering analyses,including measurements of the signature of baryon acoustic oscillationsand redshift-space distortions, based on a set of mock catalogues of thefinal SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). Ourresults show that the region of the parameter space allowed by theconsensus constraints is smaller than that of the individual methods,highlighting the importance of performing multiple analyses on galaxysurveys even when the measurements are highly correlated. This paper ispart of a set that analyses the final galaxy clustering data set fromBOSS. The methodology presented here is used in Alam et al. to producethe final cosmological constraints from BOSS.

We perform a tomographic baryon acoustic oscillations (BAO) analysisusing the monopole, quadrupole and hexadecapole of the redshift-spacegalaxy power spectrum measured from the pre-reconstructed combinedgalaxy sample of the completed Sloan Digital Sky Survey BaryonOscillation Spectroscopic Survey (BOSS) Data Release12 covering theredshift range of 0.20 < z < 0.75. By allowing for overlap betweenneighbouring redshift slices, we successfully obtained the isotropic andanisotropic BAO distance measurements within nine redshift slices to aprecision of 1.5-3.4 per cent for D_V/r_d, 1.8-4.2per cent for D_A/r_d and 3.7-7.5 per cent for Hr_d, depending on effective redshifts. We provide our BAOmeasurement of D_A/r_d and H r_d with thefull covariance matrix, which can be used for cosmological implications.Our measurements are consistent with those presented in Alam et al., inwhich the BAO distances are measured at three effective redshifts. Weconstrain dark energy parameters using our measurements and find animprovement of the Figure-of-Merit of dark energy in general due to thetemporal BAO information resolved. This paper is a part of a set thatanalyses the final galaxy clustering data set from BOSS.

We perform a tomographic baryon acoustic oscillations (BAOs) analysisusing the two-point galaxy correlation function measured from thecombined sample of Baryon Oscillation Spectroscopic Survey Data Release12 (BOSS DR12), which covers the redshift range of 0.2 < z < 0.75.Upon splitting the sample into multiple overlapping redshift slices toextract the redshift information of galaxy clustering, we obtain ameasurement of D_A(z)/r_d and H(z)r_d atnine effective redshifts with the full covariance matrix calibratedusing MultiDark-Patchy mock catalogues. Using the reconstructed galaxycatalogues, we obtain the precision of 1.3-2.2 per cent forD_A(z)/r_d and 2.1-6.0 per cent forH(z)r_d. To quantify the gain from the tomographicinformation, we compare the constraints on the cosmological parametersusing our nine-bin BAO measurements, the consensus three-bin BAO andredshift space distortion measurements at three effective redshifts inAlam et al., and the non-tomographic (one-bin) BAO measurement at asingle effective redshift. Comparing the nine-bin with one-binconstraint result, it can improve the dark energy Figure of Merit by afactor of 1.24 for the Chevallier-Polarski-Linder parametrization forequation-of-state parameter w_DE. The errors of w₀and w_a from nine-bin constraints are slightly improved whencompared to the three-bin constraint result.

We present a Bayesian phase-space reconstruction of the cosmiclarge-scale matter density and velocity fields from the Sloan DigitalSky Survey-III Baryon Oscillations Spectroscopic Survey Data Release 12CMASS galaxy clustering catalogue. We rely on a given Λ cold darkmatter cosmology, a mesh resolution in the range of 6-10 h^-1Mpc, and a lognormal-Poisson model with a redshift-dependent non-linearbias. The bias parameters are derived from the data and a generalrenormalized perturbation theory approach. We use combined Gibbs andHamiltonian sampling, implemented in the argo code, to iterativelyreconstruct the dark matter density field and the coherent peculiarvelocities of individual galaxies, correcting hereby for coherentredshift space distortions. Our tests relying on accurate N-body-basedmock galaxy catalogues show unbiased real space power spectra of thenon-linear density field up to k ˜ 0.2 h Mpc^-1, andvanishing quadrupoles down to r ˜ 20 h^-1 Mpc. We alsodemonstrate that the non-linear cosmic web can be obtained from thetidal field tensor based on the Gaussian component of the reconstructeddensity field. We find that the reconstructed velocities have astatistical correlation coefficient compared to the true velocities ofeach individual light-cone mock galaxy of r ˜ 0.68 including about10 per cent of satellite galaxies with virial motions (about r = 0.75without satellites). The power spectra of the velocity divergence agreewell with theoretical predictions up to k ˜ 0.2 h Mpc^-1.This work will be especially useful to improve, for example, baryonacoustic oscillation reconstructions, kinematic Sunyaev-Zeldovich,integrated Sachs-Wolfe measurements or environmental studies.

We explore the cosmological implications of anisotropic clusteringmeasurements in configuration space of the final galaxy samples fromData Release 12 of the Sloan Digital Sky Survey III Baryon OscillationSpectroscopic Survey. We implement a new detailed modelling of theeffects of non-linearities, bias and redshift-space distortions that canbe used to extract unbiased cosmological information from ourmeasurements for scales s ≳ 20 h^-1 Mpc. We combined theinformation from Baryon Oscillation Spectroscopic Survey (BOSS) with thelatest cosmic microwave background (CMB) observations and Type Iasupernovae samples and found no significant evidence for a deviationfrom the Λ cold dark matter (ΛCDM) cosmological model. Inparticular, these data sets can constrain the dark energyequation-of-state parameter to w_DE = -0.996 ± 0.042when to be assumed time independent, the curvature of the Universe toΩ_k = -0.0007 ± 0.0030 and the sum of theneutrino masses to ∑m_ν < 0.25 eV at 95 per centconfidence levels. We explore the constraints on the growth rate ofcosmic structures assuming f(z) =Ω_m(z)^γ and obtain γ = 0.609± 0.079, in good agreement with the predictions of generalrelativity of γ = 0.55. We compress the information of ourclustering measurements into constraints on the parameter combinationsD_V(z)/r_d, F_AP(z) andfσ₈(z) at z_eff = 0.38, 0.51 and 0.61 withtheir respective covariance matrices and find good agreement with thepredictions for these parameters obtained from the best-fittingΛCDM model to the CMB data from the Planck satellite. This paperis part of a set that analyses the final galaxy clustering data set fromBOSS. The measurements and likelihoods presented here are combined withothers by Alam et al. to produce the final cosmological constraints fromBOSS.

We investigate the anisotropic clustering of the Baryon OscillationSpectroscopic Survey (BOSS) Data Release 12 sample, which consists of1198 006 galaxies in the redshift range 0.2 < z < 0.75 and a skycoverage of 10 252 deg². We analyse this data set in Fourierspace, using the power-spectrum multipoles to measure redshift-spacedistortions simultaneously with the Alcock-Paczynski effect and thebaryon acoustic oscillation scale. We include the power-spectrummonopole, quadrupole and hexadecapole in our analysis and compare ourmeasurements with a perturbation-theory-based model, while properlyaccounting for the survey window function. To evaluate the reliabilityof our analysis pipeline, we participate in a mock challenge, whichresults in systematic uncertainties significantly smaller than thestatistical uncertainties. While the high-redshift constraint onfσ₈ at z_eff = 0.61 indicates a small(˜1.4σ) deviation from the prediction of the PlanckΛCDM (Λ cold dark matter) model, the low-redshiftconstraint is in good agreement with Planck ΛCDM. This paper ispart of a set that analyses the final galaxy clustering data set fromBOSS. The measurements and likelihoods presented here are combined withothers in Alam et al. to produce the final cosmological constraints fromBOSS.

We probe the higher order clustering of the galaxies in the final datarelease (DR12) of the Sloan Digital Sky Survey Baryon OscillationSpectroscopic Survey (BOSS), using the method of germ-grain Minkowskifunctionals (MFs). Our sample consists of 410 615 BOSS galaxies from thenorthern Galactic cap in the redshift range 0.450-0.595. We show the MFsto be sensitive to contributions up to the six-point correlationfunction for this data set. We ensure with a custom angular mask thatthe results are more independent of boundary effects than in previousanalyses of this type. We extract the higher order part of the MFs andquantify the difference to the case without higher order correlations.The resulting χ² value of over 10 000 for a modest numberof degrees of freedom, O(200), indicates a 100σ deviation anddemonstrates that we have a highly significant signal of thenon-Gaussian contributions to the galaxy distribution. This statisticalpower can be useful in testing models with differing higher ordercorrelations. Comparing the galaxy data to the quick particle mesh andMultiDark(MD)-Patchy mocks, we find that the latter better describes theobserved structure. From an order-by-order decomposition, we expectthat, for example, already a reduction of the amplitude of the MD-Patchymock power spectrum by 5 per cent would remove the remaining tension.