Cosmic shear measurements with Dark Energy Survey science verification data
Cosmic shear measurements with Dark Energy Survey science verification data
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DOI：
10.1103/physrevd.94.022002
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发表时间：
2015-04
影响因子：
5
通讯作者：
M. Becker;M. Troxel;N. MacCrann;E. Krause;T. Eifler;O. Friedrich;A. Nicola;A. Réfrégier;A. Ama
中科院分区：
文献类型：
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作者：
M. Becker;M. Troxel;N. MacCrann;E. Krause;T. Eifler;O. Friedrich;A. Nicola;A. Réfrégier;A. Ama
我们目前的测量弱引力透镜宇宙剪切两点统计使用暗能量调查科学验证数据。我们证明了我们的结果对剪切测量管道的选择是鲁棒的，无论是ngmix还是im3shape，并且对两点统计的选择是鲁棒的，包括真实的和傅立叶空间统计。我们的结果通过了一套零测试，包括测试B模式污染和直接测试的任何依赖的两点函数上的一组16个观测条件和星系的属性，如看到，空气质量，星系的颜色，星系的大小等，我们还使用了一个大的模拟套件来计算宇宙剪切测量的协方差矩阵，并分配统计意义，我们的零测试。我们发现我们的协方差矩阵与晕轮模型预测一致，表明它具有适当水平的晕轮样本方差。我们比较了相同的刀切程序应用于数据和模拟，以寻找其他来源的噪声没有捕捉到的模拟。我们在数据中没有发现统计上显著的额外噪声源。对于我们的最高源密度目录，断层扫描的总体检测显著性为9.7西格玛。这项工作中测量的宇宙学约束在一篇配套论文中提出[DES等人，D 94，022001（2016）.]。
We present measurements of weak gravitational lensing cosmic shear two-point statistics using Dark Energy Survey Science Verification data. We demonstrate that our results are robust to the choice of shear measurement pipeline, either ngmix or im3shape, and robust to the choice of two-point statistic, including both real and Fourier-space statistics. Our results pass a suite of null tests including tests for B-mode contamination and direct tests for any dependence of the two-point functions on a set of 16 observing conditions and galaxy properties, such as seeing, airmass, galaxy color, galaxy magnitude, etc. We furthermore use a large suite of simulations to compute the covariance matrix of the cosmic shear measurements and assign statistical significance to our null tests. We find that our covariance matrix is consistent with the halo model prediction, indicating that it has the appropriate level of halo sample variance. We compare the same jackknife procedure applied to the data and the simulations in order to search for additional sources of noise not captured by the simulations. We find no statistically significant extra sources of noise in the data. The overall detection significance with tomography for our highest source density catalog is 9.7 sigma . Cosmological constraints from the measurements in this work are presented in a companion paper [DES et al., Phys. Rev. D 94, 022001 (2016).].