KiDS-450: cosmological parameter constraints from tomographic weak gravitational lensing
KiDS-450: cosmological parameter constraints from tomographic weak gravitational lensing
复制标题
DOI：
10.1093/mnras/stw2805
复制
发表时间：
2016-06
影响因子：
4.8
通讯作者：
H. Hildebrandt;M. Viola;C. Heymans;S. Joudaki;K. Kuijken;C. Blake;T. Erben;B. Joachimi;D. Klaes
中科院分区：
文献类型：
--
作者：
H. Hildebrandt;M. Viola;C. Heymans;S. Joudaki;K. Kuijken;C. Blake;T. Erben;B. Joachimi;D. Klaes
我们提出了宇宙学参数的限制，从断层扫描弱引力透镜分析的~ 450度^2 $的成像数据从千度调查（KiDS）。对于一个平坦的$\Lambda$CDM宇宙学，在包含最近直接测量的$H_0$上具有先验，我们发现$S_8\equiv\sigma_8\sqrt{\Omega_{\rm m}/0.3}=0.745\pm0.039$。这一结果与其他大尺度结构的低红移探测，包括最近的宇宙剪切结果，沿着与前普朗克宇宙微波背景约束，是很好的协议。A $2.3$-$\sigma$张力在$S_8$和“实质性的不一致”在全参数空间被发现相对于普朗克2015年的结果。我们使用剪切测量近1500万个星系，确定了一个新的改进的“自校准”版本的$透镜$适合验证使用一套广泛的图像模拟。四波段的ugri测光红移直接用深谱学测量标定。红移校准确认使用两个独立的技术的基础上的角度互相关和光度红移概率分布的属性。我们的协方差矩阵确定使用的分析方法，验证数值与大型模拟星系目录。我们占的不确定性建模的内在星系的路线和重子反馈的非线性物质功率谱的形状的影响，除了剪切和红移校准的小残留的不确定性。宇宙学分析是盲法进行的。我们的高级数据产品，包括剪切相关函数，协方差矩阵，红移分布和蒙特卡罗马尔可夫链，可在http://kids.strw.leidenuniv.nl上获得。
We present cosmological parameter constraints from a tomographic weak gravitational lensing analysis of ~450deg$^2$ of imaging data from the Kilo Degree Survey (KiDS). For a flat $\Lambda$CDM cosmology with a prior on $H_0$ that encompasses the most recent direct measurements, we find $S_8\equiv\sigma_8\sqrt{\Omega_{\rm m}/0.3}=0.745\pm0.039$. This result is in good agreement with other low redshift probes of large scale structure, including recent cosmic shear results, along with pre-Planck cosmic microwave background constraints. A $2.3$-$\sigma$ tension in $S_8$ and `substantial discordance' in the full parameter space is found with respect to the Planck 2015 results. We use shear measurements for nearly 15 million galaxies, determined with a new improved `self-calibrating' version of $lens$fit validated using an extensive suite of image simulations. Four-band $ugri$ photometric redshifts are calibrated directly with deep spectroscopic surveys. The redshift calibration is confirmed using two independent techniques based on angular cross-correlations and the properties of the photometric redshift probability distributions. Our covariance matrix is determined using an analytical approach, verified numerically with large mock galaxy catalogues. We account for uncertainties in the modelling of intrinsic galaxy alignments and the impact of baryon feedback on the shape of the non-linear matter power spectrum, in addition to the small residual uncertainties in the shear and redshift calibration. The cosmology analysis was performed blind. Our high-level data products, including shear correlation functions, covariance matrices, redshift distributions, and Monte Carlo Markov Chains are available at http://kids.strw.leidenuniv.nl.