Weak lensing from space: first cosmological constraints from three-point shear statistics★
Weak lensing from space: first cosmological constraints from three-point shear statistics★
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DOI：
10.1111/j.1365-2966.2010.17430.x
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发表时间：
2010-05
影响因子：
4.8
通讯作者：
E. Semboloni;T. Schrabback;L. Waerbeke;S. Vafaei;J. Hartlap;S. Hilbert
中科院分区：
文献类型：
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作者：
E. Semboloni;T. Schrabback;L. Waerbeke;S. Vafaei;J. Hartlap;S. Hilbert
我们使用哈勃太空望远镜COSMOS巡天的弱透镜数据来测量宇宙剪切场的二阶和三阶矩，估计约450 000个星系的平均红移z ~ 1.3。我们使用树码测量两点和三点剪切统计，将信号分为E、B和混合分量。我们提出了一个检测的光圈质量统计的三阶矩，并验证测量是强大的对点扩散函数（PSF）的残差和星系之间的内在对齐所造成的系统误差。测得的三点宇宙剪切信号的振幅与7年威尔金森微波各向异性探测器（WMAP 7）最佳拟合模型的预测非常一致，而潜在系统的振幅与零一致。我们利用三套大的Lambda冷暗物质（ACDM）模拟来测试宇宙学预测的准确性，并估计宇宙学相关协方差的影响。我们使用Ω M 3 ap θ的测量值进行了似然分析，发现Ω m - σ 8简并方向很好地拟合于以下关系：（Ω m /0.30）0.49 = 0.78 + 0.11 - 0.26，这与通过测量Δ M 2 ap θ获得的最佳拟合关系非常一致：σ 8（Ω m /0.30）0.67 = 0.70 +0.11 -0.14。我们给出了更广义的三点剪切统计量的首次测量结果，并发现与WMAP 7最佳拟合宇宙学非常一致。宇宙学解释给出σ 8（Ω m /0.30）0.46 = 0.69 +0.08 -0.14。此外，对α M 3 ap β（θ 1，θ 2，θ 3）和α M 3 ap β（θ）的联合似然分析将宇宙学约束的精度提高到σ 8（Ω m /0.30）0.50 = 0.69 + 0.07 - 0.12，表明这种测量组合在推断宇宙学约束方面具有很高的潜力。
We use weak lensing data from the Hubble Space Telescope COSMOS survey to measure the second- and third-order moments of the cosmic shear field, estimated from about 450 000 galaxies with average redshift z ~ 1.3. We measure two- and three-point shear statistics using a tree-code, dividing the signal in E, B and mixed components. We present a detection of the third-order moment of the aperture mass statistic and verify that the measurement is robust against systematic errors caused by point spread function (PSF) residuals and by the intrinsic alignments between galaxies. The amplitude of the measured three-point cosmic shear signal is in very good agreement with the predictions for a 7-yr Wilkinson Microwave Anisotropy Probe (WMAP7) best-fitting model, whereas the amplitudes of potential systematics are consistent with zero. We make use of three sets of large Lambda cold dark matter (ACDM) simulations to test the accuracy of the cosmological predictions and to estimate the influence of the cosmology-dependent covariance. We perform a likelihood analysis using the measurement of 〈M 3 ap 〉(θ) and find that the Ω m - σ 8 degeneracy direction is well fitted by the relation: σ 8 (Ω m /0.30) 0.49 = 0.78 +0.11 -0.26 which is in good agreement with the best-fitting relation obtained by using the measurement of 〈M 2 ap 〉(θ): σ 8 (Ω m /0.30) 0.67 = 0.70 +0.11 -0.14 . We present the first measurement of the more generalized three-point shear statistic 〈M 3 ap 〉(θ 1 , θ 2 , θ 3 ) and find a very good agreement with the WMAP7 best-fitting cosmology. The cosmological interpretation of 〈M 3 ap 〉(θ 1 , 0 2 , θ 3 ) gives σ 8 (Ω m /0.30) 0.46 = 0.69 +0.08 -0.14 . Furthermore, the combined likelihood analysis of 〈M 3 ap 〉(θ 1 , θ 2 , θ 3 ) and 〈M 3 ap 〉(θ) improves the accuracy of the cosmological constraints to σ 8 (Ω m /0.30) 0.50 = 0.69 +0.07 -0.12 , showing the high potential of this combination of measurements to infer cosmological constraints.