arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2007.10456astro-ph.CO
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寻找随机引力波背景与星系数的互相关

Searching for Cross-Correlation Between Stochastic Gravitational Wave Background and Galaxy Number Counts

Kate Ziyan Yang, Vuk Mandic, Claudia Scarlata, Sharan Banagiri

摘要:

Advanced LIGO和Advanced Virgo最近公布了基于其第一次和第二次观测运行(O1和O2)数据的持续定向随机引力波背景(SGWB)上限测量结果。在本文中,我们调查是否存在这种最大似然SGWB地图和宇宙中的物质结构的电磁示踪剂,如星系数计数之间的相关性。我们开发的方法将提高未来搜索SGWB各向异性的灵敏度,并扩展SGWB各向异性的使用,以探测宇宙中结构的形成。为了计算互相关,我们在多个频带上使用SGWB的球谐分解,并将它们转换为基于HEALPix基的基于像素的天空图。对于电磁(EM)的一部分,我们使用斯隆数字巡天(SDSS)星系目录和形式HEALPix的星系数计数天空地图在相同的角分辨率的SGWB地图。我们计算这些SGWB和星系计数地图之间的基于像素的相干性。在评估我们的结果在不同的SGWB频带和不同的星系红移箱,我们的结论是,SGWB和星系数计数地图之间的相干性是占主导地位的SGWB地图中的零测量噪声,因此没有统计学意义。我们预计,通过使用基于Advanced LIGO和Advanced Virgo的第三次观测运行(O3)的更灵敏的SGWB测量,这种分析的结果将得到显着改善。

英文摘要:

Advanced LIGO and Advanced Virgo have recently published the upper limit measurement of persistent directional stochastic gravitational wave background (SGWB) based on data from their first and second observing runs (O1 and O2). In this paper we investigate whether a correlation exists between this maximal likelihood SGWB map and the electromagnetic tracers of matter structure in the universe, such as galaxy number counts. The method we develop will improve the sensitivity of future searches for anisotropy in the SGWB and expand the use of SGWB anisotropy to probe the formation of structure in the universe. In order to compute the cross-correlation, we used the spherical harmonic decomposition of SGWB in multiple frequency bands and converted them into pixel-based sky maps in HEALPix basis. For the electromagnetic (EM) part, we use the Sloan Digital Sky Survey (SDSS) galaxy catalog and form HEALPix sky maps of galaxy number counts at the same angular resolution as the SGWB maps. We compute the pixel-based coherence between these SGWB and galaxy count maps. After evaluating our results in different SGWB frequency bands and in different galaxy redshift bins, we conclude that the coherence between the SGWB and galaxy number count maps is dominated by the null measurement noise in the SGWB maps, and therefore not statistically significant. We expect the results of this analysis to be significantly improved by using the more sensitive upcoming SGWB measurements based on the third observing run (O3) of Advanced LIGO and Advanced Virgo.

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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