HSC Year 1 cosmology results with the minimal bias method: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>HSC</mml:mi><mml:mo stretchy="false">×</mml:mo><mml:mi>BOSS</mml:mi><mml:mrow/></mml:mrow></mml:math> galaxy-galaxy weak lensing and BOSS galaxy clustering
Sunao Sugiyama, Masahiro Takada, Hironao Miyatake, Takahiro Nishimichi, Masato Shirasaki, Yosuke Kobayashi, Rachel Mandelbaum, Surhud More, Ryuichi Takahashi, Ken Osato, Masamune Oguri, Jean Coupon, Chiaki Hikage, Bau-Ching Hsieh, Yutaka Komiyama, Alexie Leauthaud, Xiangchong Li, Wentao Luo, Robert H. Lupton, Hitoshi Murayama, Atsushi J. Nishizawa, Youngsoo Park, Paul A. Price, Melanie Simet, Joshua S. Speagle, Michael A. Strauss, Masayuki Tanaka
Abstract
We present cosmological parameter constraints from a blinded joint analysis of galaxy-galaxy weak lensing, $\mathrm{\ensuremath{\Delta}}\mathrm{\ensuremath{\Sigma}}(R)$, and the projected correlation function, ${w}_{\mathrm{p}}(R)$, measured from the first-year HSC (HSC-Y1) data and SDSS spectroscopic galaxies over $0.15<z<0.7$. We use luminosity-limited samples as lens samples for $\mathrm{\ensuremath{\Delta}}\mathrm{\ensuremath{\Sigma}}$ and as large-scale structure tracers for ${w}_{\mathrm{p}}$ in three redshift bins, and use the HSC-Y1 galaxy catalog to define a secure sample of source galaxies at ${z}_{\mathrm{ph}}>0.75$ for the $\mathrm{\ensuremath{\Delta}}\mathrm{\ensuremath{\Sigma}}$ measurements, selected based on their photometric redshifts. As a theoretical template, we use the ``minimal bias'' model for the cosmological clustering observables for the flat $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ cosmological model. We compare the model predictions with the measurements in each redshift bin on large scales, $R>12$ and $8{h}^{\ensuremath{-}1}\text{ }\text{ }\mathrm{Mpc}$ for $\mathrm{\ensuremath{\Delta}}\mathrm{\ensuremath{\Sigma}}(R)$ and ${w}_{\mathrm{p}}(R)$, respectively, where the perturbation-theory-inspired model is valid. As part of our model, we account for the effect of lensing magnification bias on the $\mathrm{\ensuremath{\Delta}}\mathrm{\ensuremath{\Sigma}}$ measurements. When we employ weak priors on cosmological parameters, without cosmic microwave background (CMB) information, we find ${S}_{8}=0.93{6}_{\ensuremath{-}0.086}^{+0.092}$, ${\ensuremath{\sigma}}_{8}=0.8{5}_{\ensuremath{-}0.11}^{+0.16}$, and ${\mathrm{\ensuremath{\Omega}}}_{\mathrm{m}}=0.28{3}_{\ensuremath{-}0.035}^{+0.12}$ (mode and 68% credible interval) for the flat $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model. Although the central value of ${S}_{8}$ appears to be larger than those inferred from other cosmological experiments, we find that the difference is consistent with expected differences due to sample variance, and our results are consistent with the other results to within the statistical uncertainties. When combined with the Planck 2018 likelihood for the primary CMB anisotropy information ($\mathrm{TT},\mathrm{TE},\mathrm{EE}+\mathrm{lowE}$), we find ${S}_{8}=0.81{7}_{\ensuremath{-}0.021}^{+0.022}$, ${\ensuremath{\sigma}}_{8}=0.89{2}_{\ensuremath{-}0.056}^{+0.051}$, ${\mathrm{\ensuremath{\Omega}}}_{\mathrm{m}}=0.24{6}_{\ensuremath{-}0.035}^{+0.045}$, and the equation-of-state parameter of dark energy, ${w}_{\mathrm{de}}=\ensuremath{-}1.2{8}_{\ensuremath{-}0.19}^{+0.20}$ for the flat $w\mathrm{CDM}$ model, which is consistent with the flat $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model to within the error bars.