Cosmology from cosmic shear power spectra with Subaru Hyper Suprime-Cam first-year data

Chiaki Hikage, Masamune Oguri, Takashi Hamana, Surhud More, Rachel Mandelbaum, Masahiro Takada, Fabian Köhlinger, Hironao Miyatake, Atsushi J. Nishizawa, Hiroaki Aihara, Robert Armstrong, James Bosch, Jean Coupon, Anne Ducout, Paul Ho, Bau Ching Hsieh, Yutaka Komiyama, François Lanusse, Alexie Leauthaud, Robert H. LuptonElinor Medezinski, Sogo Mineo, Shoken Miyama, Satoshi Miyazaki, Ryoma Murata, Hitoshi Murayama, Masato Shirasaki, Cristóbal Sifón, Melanie Simet, Joshua Speagle, David N. Spergel, Michael A. Strauss, Naoshi Sugiyama, Masayuki Tanaka, Yousuke Utsumi, Shiang Yu Wang, Yoshihiko Yamada

Research output: Contribution to journalArticlepeer-review

420 Scopus citations


We measure cosmic weak lensing shear power spectra with the Subaru Hyper Suprime- Cam (HSC) survey first-year shear catalog covering 137 deg2 of the sky. Thanks to the high effective galaxy number density of ∼17 arcmin-2, even after conservative cuts such as a magnitude cut of i < 24.5 and photometric redshift cut of 0.3 ≤ z ≤ 1.5, we obtain a high-significance measurement of the cosmic shear power spectra in four tomographic redshift bins, achieving a total signal-to-noise ratio of 16 in the multipole range 300 ≤ ℓ ≤ 1900. We carefully account for various uncertainties in our analysis including the intrinsic alignment of galaxies, scatters and biases in photometric redshifts, residual uncertainties in the shear measurement, and modeling of the matter power spectrum. The accuracy of our power spectrummeasurement method as well as our analytic model of the covariance matrix are tested against realistic mock shear catalogs. For a flat ∧ cold dark matter model, we find S8 ≡ σ8m/0.3)α = 0.800+0.029-0.028 for α = 0.45 (S8 = 0.780+0.030-0.033 for α = 0.5) from our HSC tomographic cosmic shear analysis alone. In comparison with Planck cosmic microwave background constraints, our results prefer slightly lower values of S8, although metrics such as the Bayesian evidence ratio test do not show significant evidence for discordance between these results. We study the effect of possible additional systematic errors that are unaccounted for in our fiducial cosmic shear analysis, and find that they can shift the best-fit values of S8 by up to ∼0.6 σ in both directions. The full HSC survey data will contain several times more area, and will lead to significantly improved cosmological constraints.

Original languageEnglish (US)
Article number43
JournalPublications of the Astronomical Society of Japan
Issue number2
StatePublished - Apr 1 2019

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Dark matter
  • Gravitational lensing: weak
  • Large-scale structure of universe


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