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arXiv 1607.02875astro-ph.GAastro-ph.CO
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COSMOS场中的射电-光学星系形状关联

Radio-Optical Galaxy Shape Correlations in the COSMOS Field

Ben Tunbridge, Ian Harrison, Michael L. Brown

备注：
17 pages, 13 figure, 5 tables. Updated to match published version with a number of typographical corrections
发表信息：
Monthly Notices of the Royal Astronomical Society 2016, Volume 463, Issue 3, Pp. 3339-3353
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摘要：

我们调查的相关性星系形状之间的光学和无线电波长使用档案观测的宇宙领域。不同波段之间的互相关研究对于精确宇宙学将变得越来越重要，因为未来的大型调查可能会被系统误差而不是统计误差所主导。在弱透镜的情况下，星系的形状必须被测量到非常精确的程度（$< 0.01\%$的剪切系统学），以实现对暗能量参数的良好约束。通过使用来自光学和无线电频带中的重叠调查的形状信息，可以显著提高系统学的鲁棒性而不损失约束力。在这里，我们使用HST-ACS的光学数据，VLA无线电数据，和广泛的模拟调查我们的能力，使精确测量的源形状从现实的无线电数据，并约束内在的天体物理散射的星系的形状之间的测量在光学和无线电波段。通过从VLA-COSMOS L波段射电可见度数据中产生一个非常适合星系形状测量的新图像，我们能够提取星系位置角的精确测量值。与HST光学图像的相应测量值相比，我们在$95\%$置信水平下，对$σ_α> 0.212π$弧度（或$38.2^{\circ}$）的光学和无线电波段之间的位置角中的内在天体物理散射设置了下限。

英文摘要：

We investigate the correlations in galaxy shapes between optical and radio wavelengths using archival observations of the COSMOS field. Cross-correlation studies between different wavebands will become increasingly important for precision cosmology as future large surveys may be dominated by systematic rather than statistical errors. In the case of weak lensing, galaxy shapes must be measured to extraordinary accuracy (shear systematics of $< 0.01\%$) in order to achieve good constraints on dark energy parameters. By using shape information from overlapping surveys in optical and radio bands, robustness to systematics may be significantly improved without loss of constraining power. Here we use HST-ACS optical data, VLA radio data, and extensive simulations to investigate both our ability to make precision measurements of source shapes from realistic radio data, and to constrain the intrinsic astrophysical scatter between the shapes of galaxies as measured in the optical and radio wavebands. By producing a new image from the VLA-COSMOS L-band radio visibility data that is well suited to galaxy shape measurements, we are able to extract precise measurements of galaxy position angles. Comparing to corresponding measurements from the HST optical image, we set a lower limit on the intrinsic astrophysical scatter in position angles, between the optical and radio bands, of $σ_α> 0.212π$ radians (or $38.2^{\circ}$) at a $95\%$ confidence level.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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