scholarly journals The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: 1000 multi-tracer mock catalogues with redshift evolution and systematics for galaxies and quasars of the final data release

2021 ◽  
Vol 503 (1) ◽  
pp. 1149-1173 ◽  
Author(s):  
Cheng Zhao ◽  
Chia-Hsun Chuang ◽  
Julian Bautista ◽  
Arnaud de Mattia ◽  
Anand Raichoor ◽  
...  
Keyword(s):  
Configuration Space ◽  
Sample Selection ◽  
Acoustic Oscillation ◽  
Fourier Space ◽  
Bias Model ◽  
Data Release ◽  
Final Data ◽  
Systematic Effects ◽  
Space Distortion ◽  
Cross Correlations

ABSTRACT We produce 1000 realizations of synthetic clustering catalogues for each type of the tracers used for the baryon acoustic oscillation and redshift space distortion analysis of the Sloan Digital Sky Surveys-iv extended Baryon Oscillation Spectroscopic Survey final data release (eBOSS DR16), covering the redshift range from 0.6 to 2.2, to provide reliable estimates of covariance matrices and test the robustness of the analysis pipeline with respect to observational systematics. By extending the Zel’dovich approximation density field with an effective tracer bias model calibrated with the clustering measurements from the observational data, we accurately reproduce the two- and three-point clustering statistics of the eBOSS DR16 tracers, including their cross-correlations in redshift space with very low computational costs. In addition, we include the gravitational evolution of structures and sample selection biases at different redshifts, as well as various photometric and spectroscopic systematic effects. The agreements on the auto-clustering statistics between the data and mocks are generally within $1\, \sigma$ variances inferred from the mocks, for scales down to a few $h^{-1}\, {\rm Mpc}$ in configuration space, and up to $0.3\, h\, {\rm Mpc}^{-1}$ in Fourier space. For the cross correlations between different tracers, the same level of consistency presents in configuration space, while there are only discrepancies in Fourier space for scales above $0.15\, h\, {\rm Mpc}^{-1}$. The accurate reproduction of the data clustering statistics permits reliable covariances for multi-tracer analysis.

scholarly journals The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: N-body mock challenge for the quasar sample

2020 ◽  
Vol 499 (1) ◽  
pp. 269-291 ◽  
Author(s):  
Alex Smith ◽  
Etienne Burtin ◽  
Jiamin Hou ◽  
Richard Neveux ◽  
Ashley J Ross ◽  
...  
Keyword(s):  
Final Analysis ◽  
Systematic Errors ◽  
Acoustic Oscillation ◽  
Sloan Digital Sky Survey ◽  
Fourier Space ◽  
Redshift Surveys ◽  
Sky Survey ◽  
History Of ◽  
Space Distortion ◽  
Halo Occupation Distribution

ABSTRACT The growth rate and expansion history of the Universe can be measured from large galaxy redshift surveys using the Alcock–Paczynski effect. We validate the Redshift Space Distortion models used in the final analysis of the Sloan Digital Sky Survey (SDSS) extended Baryon Oscillation Spectroscopic Survey (eBOSS) Data Release 16 quasar clustering sample, in configuration and Fourier space, using a series of halo occupation distribution mock catalogues generated using the OuterRim N-body simulation. We test three models on a series of non-blind mocks, in the OuterRim cosmology, and blind mocks, which have been rescaled to new cosmologies, and investigate the effects of redshift smearing and catastrophic redshifts. We find that for the non-blind mocks, the models are able to recover fσ8 to within 3 per cent and α∥ and α⊥ to within 1 per cent. The scatter in the measurements is larger for the blind mocks, due to the assumption of an incorrect fiducial cosmology. From this mock challenge, we find that all three models perform well, with similar systematic errors on fσ8, α∥, and α⊥ at the level of $\sigma _{f\sigma _8}=0.013$, $\sigma _{\alpha _\parallel }=0.012$, and $\sigma _{\alpha _\bot }=0.008$. The systematic error on the combined consensus is $\sigma _{f\sigma _8}=0.011$, $\sigma _{\alpha _\parallel }=0.008$, and $\sigma _{\alpha _\bot }=0.005$, which is used in the final DR16 analysis. For baryon acoustic oscillation fits in configuration and Fourier space, we take conservative systematic errors of $\sigma _{\alpha _\parallel }=0.010$ and $\sigma _{\alpha _\bot }=0.007$.

scholarly journals Tests of redshift-space distortions models in configuration space for the analysis of the BOSS final data release

2014 ◽  
Vol 447 (1) ◽  
pp. 234-245 ◽  
Author(s):  
Martin White ◽  
Beth Reid ◽  
Chia-Hsun Chuang ◽  
Jeremy L. Tinker ◽  
Cameron K. McBride ◽  
...  
Keyword(s):  
Configuration Space ◽  
Data Release ◽  
Final Data

scholarly journals The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: BAO and RSD measurements from the anisotropic power spectrum of the quasar sample between redshift 0.8 and 2.2

2020 ◽  
Vol 499 (1) ◽  
pp. 210-229 ◽  
Author(s):  
Richard Neveux ◽  
Etienne Burtin ◽  
Arnaud de Mattia ◽  
Alex Smith ◽  
Ashley J Ross ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Configuration Space ◽  
Linear Growth ◽  
Statistical Error ◽  
Systematic Errors ◽  
Linear Growth Rate ◽  
Consensus Analysis ◽  
Space Analysis ◽  
Data Release ◽  
Final Data

ABSTRACT We measure the clustering of quasars of the final data release (DR16) of eBOSS. The sample contains $343\, 708$ quasars between redshifts 0.8 ≤ z ≤ 2.2 over $4699\, \mathrm{deg}^2$. We calculate the Legendre multipoles (0,2,4) of the anisotropic power spectrum and perform a BAO and a Full-Shape (FS) analysis at the effective redshift zeff = 1.480. The errors include systematic errors that amount to 1/3 of the statistical error. The systematic errors comprise a modelling part studied using a blind N-body mock challenge and observational effects studied with approximate mocks to account for various types of redshift smearing and fibre collisions. For the BAO analysis, we measure the transverse comoving distance DM(zeff)/rdrag = 30.60 ± 0.90 and the Hubble distance DH(zeff)/rdrag = 13.34 ± 0.60. This agrees with the configuration space analysis, and the consensus yields: DM(zeff)/rdrag = 30.69 ± 0.80 and DH(zeff)/rdrag = 13.26 ± 0.55. In the FS analysis, we fit the power spectrum using a model based on Regularised Perturbation Theory, which includes redshift space distortions and the Alcock–Paczynski effect. The results are DM(zeff)/rdrag = 30.68 ± 0.90 and DH(zeff)/rdrag = 13.52 ± 0.51 and we constrain the linear growth rate of structure f(zeff)σ8(zeff) = 0.476 ± 0.047. Our results agree with the configuration space analysis. The consensus analysis of the eBOSS quasar sample yields: DM(zeff)/rdrag = 30.21 ± 0.79, DH(zeff)/rdrag = 3.23 ± 0.47, and f(zeff)σ8(zeff) = 0.462 ± 0.045 and is consistent with a flat ΛCDM cosmological model using Planck results.

scholarly journals The clustering of the SDSS-IV extended baryon oscillation spectroscopic survey DR16 luminous red galaxy and emission-line galaxy samples: cosmic distance and structure growth measurements using multiple tracers in configuration space

2020 ◽  
Vol 498 (3) ◽  
pp. 3470-3483 ◽  
Author(s):  
Yuting Wang ◽  
Gong-Bo Zhao ◽  
Cheng Zhao ◽  
Oliver H E Philcox ◽  
Shadab Alam ◽  
...  
Keyword(s):  
Emission Line ◽  
Configuration Space ◽  
Cross Correlation ◽  
Acoustic Oscillation ◽  
Sloan Digital Sky Survey ◽  
Joint Measurement ◽  
Angular Diameter Distance ◽  
Two Samples ◽  
Space Distortion ◽  
Line Galaxy

ABSTRACT We perform a multitracer analysis using the complete Sloan Digital Sky Survey IV (SDSS-IV) extended Baryon Oscillation Spectroscopic Survey (eBOSS) DR16 luminous red galaxy (LRG) and the DR16 emission-line galaxy (ELG) samples in the configuration space, and successfully detect a cross-correlation between the two samples, and find the growth rate to be fσ8=0.342 ± 0.085 (∼25 per cent accuracy) from the cross-sample alone. We perform a joint measurement of the baryonic acoustic oscillation (BAO) and redshift space distortion (RSD) parameters at a single effective redshift of zeff = 0.77, using the autocorrelation and cross-correlation functions of the LRG and ELG samples, and find that the comoving angular diameter distance DM(zeff)/rd = 18.85 ± 0.38, the Hubble distance DH(zeff)/rd = 19.64 ± 0.57, and fσ8(zeff) = 0.432 ± 0.038, which is consistent with a ΛCDM model at $68{\ \rm per\ cent}$ CL. Compared to the single-tracer analysis on the LRG sample, the Figure of Merit of α⊥, α∥, andfσ8 is improved by a factor of 1.11 in our multitracer analysis, and in particular, the statistical uncertainty of fσ8 is reduced by $11.6{\ \rm per\ cent}$.

scholarly journals Optimizing galaxy samples for clustering measurements in photometric surveys

2019 ◽  
Vol 491 (3) ◽  
pp. 3535-3552 ◽  
Author(s):  
Dimitrios Tanoglidis ◽  
Chihway Chang ◽  
Joshua Frieman
Keyword(s):  
Cold Dark Matter ◽  
Sample Selection ◽  
Gaussian Model ◽  
Small Subset ◽  
Data Sets ◽  
Trade Off ◽  
Cosmological Constraints ◽  
Dark Energy Survey ◽  
Galaxy Sample ◽  
Cross Correlations

ABSTRACT When analysing galaxy clustering in multiband imaging surveys, there is a trade-off between selecting the largest galaxy samples (to minimize the shot noise) and selecting samples with the best photometric redshift (photo-z) precision, which generally includes only a small subset of galaxies. In this paper, we systematically explore this trade-off. Our analysis is targeted towards the third-year data of the Dark Energy Survey (DES), but our methods hold generally for other data sets. Using a simple Gaussian model for the redshift uncertainties, we carry out a Fisher matrix forecast for cosmological constraints from angular clustering in the redshift range z = 0.2–0.95. We quantify the cosmological constraints using a figure of merit (FoM) that measures the combined constraints on Ωm and σ8 in the context of Λ cold dark matter (ΛCDM) cosmology. We find that the trade-off between sample size and photo-z precision is sensitive to (1) whether cross-correlations between redshift bins are included or not, and (2) the ratio of the redshift bin width δz to the photo-z precision σz. When cross-correlations are included and the redshift bin width is allowed to vary, the highest FoM is achieved when δz ∼ σz. We find that for the typical case of 5−10 redshift bins, optimal results are reached when we use larger, less precise photo-z samples, provided that we include cross-correlations. For samples with higher σz, the overlap between redshift bins is larger, leading to higher cross-correlation amplitudes. This leads to the self-calibration of the photo-z parameters and therefore tighter cosmological constraints. These results can be used to help guide galaxy sample selection for clustering analysis in ongoing and future photometric surveys.

scholarly journals 2MTF – VII. 2MASS Tully–Fisher survey final data release: distances for 2062 nearby spiral galaxies

2019 ◽  
Vol 487 (2) ◽  
pp. 2061-2069 ◽  
Author(s):  
Tao Hong ◽  
Lister Staveley-Smith ◽  
Karen L Masters ◽  
Christopher M Springob ◽  
Lucas M Macri ◽  
...  
Keyword(s):  
Spiral Galaxies ◽  
Data Release ◽  
Final Data

scholarly journals PECULIARITIES OF PHASES OF THE WMAP QUADRUPOLE

2008 ◽  
Vol 17 (01) ◽  
pp. 179-194 ◽  
Author(s):  
PAVEL D. NASELSKY ◽  
OLEG V. VERKHODANOV
Keyword(s):  
Gain Factor ◽  
Phase Correlation ◽  
Strong Indication ◽  
W Band ◽  
Global Trend ◽  
Data Release ◽  
Systematic Effects ◽  
One Year ◽  
The One ◽  
Simple Rotation

We present the analysis of the quadrupole phases of the Internal Linear Combination map, ILC(I) and (III), derived by the WMAP team (one- and three-year data release). This approach allows us to see the global trend of non-Gaussianity of the quadrupoles for the ILC(III) map through phase correlations with the foregrounds. Significant phase correlations are found between the ILC(III) quadrupole and the WMAP foreground phases for the K-W band: the phases of the ILC(III) quadrupole ξ2,1, ξ2,2 and those of the foregrounds at K–W bands Φ2,1, Φ2,2 display significant symmetry: ξ2,1 + Φ2,1 ≃ ξ2,2 + Φ2,2, which is a strong indication that the morphology of the ILC(III) quadrupole is a mere reflection of that the foreground quadrupole through coupling. To clarify this issue we exploit the symmetry of the CMB power, which is invariant under permutation of the index m = 1 ⇔ 2. By simple rotation of the ILC(III) phases with the same angle we reach the phases of the foreground quadrupole. We discuss possible sources of phase correlation and come to the conclusion that the phases of the ILC(III) quadrupole reflect most likely systematic effects such as changing of the gain factor for the three-year data release with respect to the one-year, rather than manifestation of the primordial non-Gaussianity.

scholarly journals The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: mock galaxy catalogues for the BOSS Final Data Release

2016 ◽  
Vol 456 (4) ◽  
pp. 4156-4173 ◽  
Author(s):  
Francisco-Shu Kitaura ◽  
Sergio Rodríguez-Torres ◽  
Chia-Hsun Chuang ◽  
Cheng Zhao ◽  
Francisco Prada ◽  
...  
Keyword(s):  
Data Release ◽  
Final Data

scholarly journals Euclid: The importance of galaxy clustering and weak lensing cross-correlations within the photometric Euclid survey

2020 ◽  
Vol 643 ◽  
pp. A70 ◽  
Author(s):  
I. Tutusaus ◽  
M. Martinelli ◽  
V. F. Cardone ◽  
S. Camera ◽  
S. Yahia-Cherif ◽  
...  
Keyword(s):  
Gravity Models ◽  
Weak Lensing ◽  
Matrix Formalism ◽  
Photometric Redshift ◽  
Bias Model ◽  
Systematic Effects ◽  
The Mean ◽  
Galaxy Bias ◽  
The Impact ◽  
Parameter Constraints

Context. The data from the Euclid mission will enable the measurement of the angular positions and weak lensing shapes of over a billion galaxies, with their photometric redshifts obtained together with ground-based observations. This large dataset, with well-controlled systematic effects, will allow for cosmological analyses using the angular clustering of galaxies (GCph) and cosmic shear (WL). For Euclid, these two cosmological probes will not be independent because they will probe the same volume of the Universe. The cross-correlation (XC) between these probes can tighten constraints and is therefore important to quantify their impact for Euclid. Aims. In this study, we therefore extend the recently published Euclid forecasts by carefully quantifying the impact of XC not only on the final parameter constraints for different cosmological models, but also on the nuisance parameters. In particular, we aim to decipher the amount of additional information that XC can provide for parameters encoding systematic effects, such as galaxy bias, intrinsic alignments (IAs), and knowledge of the redshift distributions. Methods. We follow the Fisher matrix formalism and make use of previously validated codes. We also investigate a different galaxy bias model, which was obtained from the Flagship simulation, and additional photometric-redshift uncertainties; we also elucidate the impact of including the XC terms on constraining these latter. Results. Starting with a baseline model, we show that the XC terms reduce the uncertainties on galaxy bias by ∼17% and the uncertainties on IA by a factor of about four. The XC terms also help in constraining the γ parameter for minimal modified gravity models. Concerning galaxy bias, we observe that the role of the XC terms on the final parameter constraints is qualitatively the same irrespective of the specific galaxy-bias model used. For IA, we show that the XC terms can help in distinguishing between different models, and that if IA terms are neglected then this can lead to significant biases on the cosmological parameters. Finally, we show that the XC terms can lead to a better determination of the mean of the photometric galaxy distributions. Conclusions. We find that the XC between GCph and WL within the Euclid survey is necessary to extract the full information content from the data in future analyses. These terms help in better constraining the cosmological model, and also lead to a better understanding of the systematic effects that contaminate these probes. Furthermore, we find that XC significantly helps in constraining the mean of the photometric-redshift distributions, but, at the same time, it requires more precise knowledge of this mean with respect to single probes in order not to degrade the final “figure of merit”.

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