Cosmological constraints from cosmic shear twopoint correlation functions with HSC survey firstyear data
Abstract
We present measurements of cosmic shear twopoint correlation functions (TPCFs) from Hyper SuprimeCam Subaru Strategic Program (HSC) firstyear data, and derive cosmological constraints based on a blind analysis. The HSC firstyear shape catalog is divided into four tomographic redshift bins ranging from z=0.3 to 1.5 with equal widths of ∆ z =0.3. The unweighted galaxy number densities in each tomographic bin are 5.9, 5.9, 4.3, and 2.4arcmin^{2} from the lowest to highest redshifts, respectively. We adopt the standard TPCF estimators, ξ _±, for our cosmological analysis, given that we find no evidence of significant Bmode shear. The TPCFs are detected at high significance for all 10 combinations of auto and crosstomographic bins over a wide angular range, yielding a total signaltonoise ratio of 19 in the angular ranges adopted in the cosmological analysis, 7^' }<θ <56^' } for ξ _+ and 28^' }<θ <178^' } for ξ _. We perform the standard Bayesian likelihood analysis for cosmological inference from the measured cosmic shear TPCFs, including contributions from intrinsic alignment of galaxies as well as systematic effects from PSF model errors, shear calibration uncertainty, and source redshift distribution errors. We adopt a covariance matrix derived from realistic mock catalogs constructed from fullsky gravitational lensing simulations that fully account for survey geometry and measurement noise. For a flat Λ cold dark matter model, we find S _8 ≡ σ _8√{Ω _m/0.3}=0.804_{0.029}^{+0.032}, and Ω _m=0.346_{0.100}^{+0.052}. We carefully check the robustness of the cosmological results against astrophysical modeling uncertainties and systematic uncertainties in measurements, and find that none of them has a significant impact on the cosmological constraints.
 Publication:

Publications of the Astronomical Society of Japan
 Pub Date:
 February 2020
 DOI:
 10.1093/pasj/psz138
 arXiv:
 arXiv:1906.06041
 Bibcode:
 2020PASJ...72...16H
 Keywords:

 cosmological parameters;
 cosmology: observations;
 dark matter;
 largescale structure of universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 33 pages, 28 figures, accepted for publication in PASJ. Data vector, covariance and MultiNest chains are available from http://th.nao.ac.jp/MEMBER/hamanatk/HSC16aCSTPCF/index.html