Measuring cosmic velocities with 21 cm intensity mapping and galaxy redshift survey cross-correlation dipoles
Measuring cosmic velocities with 21 cm intensity mapping and galaxy redshift survey cross-correlation dipoles
复制标题
使用 21 厘米强度映射和星系红移巡天互相关偶极子测量宇宙速度
DOI：
10.1103/physrevd.95.043530
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发表时间：
2016
影响因子：
5
通讯作者：
C. Bonvin
中科院分区：
文献类型：
--
作者：
A. Hall;C. Bonvin
本文研究了利用红移空间互相关函数的偶极测量大尺度结构中奇异速度效应的可行性。我们结合联合收割机数计数的星系与亮度温度波动从21厘米强度映射，表明偶极子可以测量在适度的意义（$\lesssim 2\sigma$）相结合，即将到来的无线电调查CHIME与未来的红移调查DESI和欧几里得。通过将SKA的强度图与DESI或欧几里得的强度图相结合，可以进行更重要的测量（$\lesssim~10\sigma$），并且通过将完全内部的观测值结合到SKA中，可以进行更高的重要性测量（$\lesssim 100\sigma$）。我们占的影响，如污染的广角条款，干涉仪噪声和光束的强度图，非线性增强的功率谱，堆叠多个人口，放大率斜率的敏感性，以及数量计数和强度图探测相同的示踪剂的可能性。我们还推导出一个新的表达式的协方差矩阵的多示踪剂红移空间相关函数估计与任意方向的权重，这可能是有用的，为即将到来的调查，旨在测量红移空间聚类与多个示踪剂。
We investigate the feasibility of measuring the effects of peculiar velocities in large-scale structure using the dipole of the redshift-space cross-correlation function. We combine number counts of galaxies with brightness-temperature fluctuations from 21cm intensity mapping, demonstrating that the dipole may be measured at modest significance ($\lesssim 2\sigma$) by combining the upcoming radio survey CHIME with the future redshift surveys of DESI and Euclid. More significant measurements ($\lesssim~10\sigma$) will be possible by combining intensity maps from the SKA with these of DESI or Euclid, and an even higher significance measurement ($\lesssim 100\sigma$) may be made by combining observables completely internally to the SKA. We account for effects such as contamination by wide-angle terms, interferometer noise and beams in the intensity maps, non-linear enhancements to the power spectrum, stacking multiple populations, sensitivity to the magnification slope, and the possibility that number counts and intensity maps probe the same tracers. We also derive a new expression for the covariance matrix of multi-tracer redshift-space correlation function estimators with arbitrary orientation weights, which may be useful for upcoming surveys aiming at measuring redshift-space clustering with multiple tracers.