Very weak lensing in the CFHTLS Wide: Cosmology from cosmic shear in the linear regime
Very weak lensing in the CFHTLS Wide: Cosmology from cosmic shear in the linear regime
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DOI：
10.1051/0004-6361:20078522
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发表时间：
2007-12
影响因子：
6.5
通讯作者：
L. Fu;L. Fu;E. Semboloni;E. Semboloni;H. Hoekstra;M. Kilbinger;M. Kilbinger;L. Waerbeke;I. Ter
中科院分区：
文献类型：
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作者：
L. Fu;L. Fu;E. Semboloni;E. Semboloni;H. Hoekstra;M. Kilbinger;M. Kilbinger;L. Waerbeke;I. Ter
目标。我们利用第三年(T0003)CFHTLS广泛发布的数据，对线性区域大尺度结构的弱透镜现象进行了探索。我们的结果严格限制了物质功率谱σ8的振幅与物质密度Ωm方法的比例关系。三个独立的区域跨越57平方度到I�=24.5度，这一史无前例的连续区域允许从1角分到4度的两点剪切统计的高信噪比测量。理解我们分析中的系统误差对于解释结果至关重要。因此，我们使用阶跃模拟、数据的E/B模式分解和恒星-星系互相关函数来证明我们方法的百分比级精度。我们还利用CFHTLS T0003深场的红移数据对星系的红移分布进行了彻底的分析，这些深场探测到了与宽场相同的空间区域。结果。对于假设的平坦宇宙学，我们使用全角尺度的口径-质量统计得到σ8(Ωm/0.25)0.64=0.785±0.043，这与WMAP3的约束条件非常一致。我们的分析探测到的最大物理尺度是85Mpc，假设透镜的平均红移为0.5%，并且是Λ清洁发展机制宇宙学。这首次允许仅使用线性区域中的宇宙剪切测量来约束宇宙学。仅用角标度θ>；85arcmin，我们得到σ_8(Ω_m/0.25)0.53Lin=0.837±0.084，这与我们的全分析结果是一致的。结合我们的结果和WMAP3的数据，我们得到Ωm=0.248±0.019，σ8=0.771±0.029。
Aims. We present an exploration of weak lensing by large-scale structure in the linear regime, using the third-year (T0003) CFHTLS Wide data release. Our results place tight constraints on the scaling of the amplitude of the matter power spectrum σ8 with the matter density Ωm. Methods. Spanning 57 square degrees to i � = 24.5 over three independent fields, the unprecedented contiguous area of this survey permits high signal-to-noise measurements of two-point shear statistics from 1 arcmin to 4 degrees. Understanding systematic errors in our analysis is vital in interpreting the results. We therefore demonstrate the percent-level accuracy of our method using STEP simulations, an E/B-mode decomposition of the data, and the star-galaxy cross correlation function. We also present a thorough analysis of the galaxy redshift distribution using redshift data from the CFHTLS T0003 Deep fields that probe the same spatial regions as the Wide fields. Results. We find σ8(Ωm/0.25) 0.64 = 0.785 ± 0.043 using the aperture-mass statistic for the full range of angular scales for an assumed flat cosmology, in excellent agreement with WMAP3 constraints. The largest physical scale probed by our analysis is 85 Mpc, assuming a mean redshift of lenses of 0.5 and a ΛCDM cosmology. This allows for the first time to constrain cosmology using only cosmic shear measurements in the linear regime. Using only angular scales θ> 85 arcmin, we find σ8(Ωm/0.25) 0.53 lin = 0.837 ± 0.084, which agree with the results from our full analysis. Combining our results with data from WMAP3, we find Ωm = 0.248 ± 0.019 and σ8 = 0.771 ± 0.029.