Cosmology from cosmic shear power spectra with Subaru Hyper Suprime-Cam first-year data
Cosmology from cosmic shear power spectra with Subaru Hyper Suprime-Cam first-year data
复制标题
DOI：
10.1093/pasj/psz010
复制
发表时间：
2018-09
影响因子：
2.3
通讯作者：
C. Hikage;M. Oguri;T. Hamana;S. More;R. Mandelbaum;M. Takada;F. Kohlinger;H. Miyatake;A. Nishizawa;H. Aihara;R. Armstrong;J. Bosch;J. Coupon;A. Ducout;P. Ho;B. Hsieh;Y. Komiyama;F. Lanusse;A. Leauthaud;R. Lupton;E. Medezinski;S. Mineo;S. Miyama;S. Miyazaki;Ryoma Murata;H. Murayama;M. Shirasaki;C. Sif'on;M. Simet;J. Speagle;D. Spergel;M. Strauss;N. Sugiyama;Masayuki Tanaka;Y. Utsumi;Shiang‐Yu Wang;Y. Yamada
中科院分区：
文献类型：
--
作者：
C. Hikage;M. Oguri;T. Hamana;S. More;R. Mandelbaum;M. Takada;F. Kohlinger;H. Miyatake;A. Nishizawa;H. Aihara;R. Armstrong;J. Bosch;J. Coupon;A. Ducout;P. Ho;B. Hsieh;Y. Komiyama;F. Lanusse;A. Leauthaud;R. Lupton;E. Medezinski;S. Mineo;S. Miyama;S. Miyazaki;Ryoma Murata;H. Murayama;M. Shirasaki;C. Sif'on;M. Simet;J. Speagle;D. Spergel;M. Strauss;N. Sugiyama;Masayuki Tanaka;Y. Utsumi;Shiang‐Yu Wang;Y. Yamada
我们测量宇宙弱透镜剪切功率谱与斯巴鲁超Suprime-Cam（HSC）调查第一年剪切目录覆盖137度2的天空。由于有效星系数密度高达1.17 arcmin−2，即使经过保守的切割，例如i < 24.5的星等切割和0.3 ≤ z ≤ 1.5的光度红移切割，我们在四个层析红移箱中获得了宇宙剪切功率谱的高显著性测量，在多极范围300 ≤ z ≤ 1900中达到了16的总信噪比。在我们的分析中，我们仔细考虑了各种不确定性，包括星系的内在排列，散射和光度红移的偏差，剪切测量中的残余不确定性，以及物质功率谱的建模。我们的功率谱测量方法的准确性，以及我们的协方差矩阵的分析模型进行了测试对现实的模拟剪切目录。对于一个平坦的Λ冷暗物质模型，我们发现当α = 0.45时，S8 =0.800^{+0.029}-0.028}$（当α = 0.5时，S8 =0.780^{+0.030}-0.033}$）。与普朗克宇宙微波背景约束相比，我们的结果更倾向于S8的略低值，尽管贝叶斯证据比检验等指标并未显示这些结果之间存在显著不一致性。我们研究了基准宇宙剪切分析中未考虑的可能的额外系统误差的影响，并发现它们可以使S8的最佳拟合值在两个方向上移动高达0.6 σ。完整的HSC调查数据将包含几倍的面积，并将导致显着改善宇宙学约束。
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 spectrum measurement method as well as our analytic model of the covariance matrix are tested against realistic mock shear catalogs. For a flat Λ cold dark matter model, we find $S\,_{8}\equiv \sigma _8(\Omega _{\rm m}/0.3)^\alpha =0.800^{+0.029}_{-0.028}$ for α = 0.45 ($S\,_8=0.780^{+0.030}_{-0.033}$ 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.