arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1809.09148astro-ph.CO
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用斯巴鲁Hyper Suprime-Cam第一年数据从宇宙剪切功率谱得到的宇宙学

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, Hiroak… 展开作者

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. Lupton, Elinor 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

摘要:

我们测量宇宙弱透镜剪切功率谱与斯巴鲁超Suprime-Cam(HSC)调查第一年的剪切目录,覆盖137度$^2$的天空。由于$\sim$ 17 arcmin $^{-2}$的高有效星系数密度,即使在保守的削减,如幅度削减$i<24.5$和光度红移削减$0.3\leq z \leq 1.5$,我们获得了高显着性测量的宇宙剪切功率谱在4个层析红移箱,实现了总的信噪比为16的多极范围$300 \leq \ell \leq 1900$。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($Λ$ CDM)模型,我们发现$S_8\equiv σ_8(Ω_{\rm m}/0.3)^α=0.800^{+0.029}_{-0.028}$的$α=0.45$($S_8=0.780^{+0.030}_{-0.033}$的$α=0.5$)从我们的HSC层析宇宙剪切分析单独。与普朗克宇宙微波背景约束相比,我们的研究结果更倾向于$S_8$的值略低,尽管贝叶斯证据比检验等指标并没有显示出这些结果之间不一致的显著证据。我们研究了在我们的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,并发现它们可以在两个方向上将$S_8$的最佳拟合值移动多达$\sim 0.6σ$。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。

英文摘要:

We measure cosmic weak lensing shear power spectra with the Subaru Hyper Suprime-Cam (HSC) survey first-year shear catalog covering 137deg$^2$ of the sky. Thanks to the high effective galaxy number density of $\sim$17 arcmin$^{-2}$ even after conservative cuts such as magnitude cut of $i<24.5$ and photometric redshift cut of $0.3\leq z \leq 1.5$, we obtain a high significance measurement of the cosmic shear power spectra in 4 tomographic redshift bins, achieving a total signal-to-noise ratio of 16 in the multipole range $300 \leq \ell \leq 1900$. 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 ($Λ$CDM) model, we find $S_8\equiv σ_8(Ω_{\rm m}/0.3)^α=0.800^{+0.029}_{-0.028}$ 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 $S_8$, 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 in our fiducial cosmic shear analysis, and find that they can shift the best-fit values of $S_8$ by up to $\sim 0.6σ$ in both directions. The full HSC survey data will contain several times more area, and will lead to significantly improved cosmological constraints.

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