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arXiv 1012.3214astro-ph.COgr-qchep-th
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利用公共X射线团簇数据测量暗流

Measuring the dark flow with public X-ray cluster data

A. Kashlinsky, F. Atrio-Barandela, H. Ebeling

摘要:

我们提出了新的结果"暗流"的偶极子的测量中的特殊速度分布的星系团,应用我们以前提出和发展的方法。我们最新的测量是使用新的,低噪声的7年WMAP数据,以及一个全天空的X射线样本选择星系团完全从出版的目录编译。我们分析的CMB签名的运动学Sunyaev-Zeldovich(SZ)的效果发现一个统计上显着的偶极子在星系团的位置。集群区域外的残余偶极子很小,使我们的整体测量3 - 4西格玛显着。偶极的振幅与簇的性质相关,对于大多数X射线发光的簇,其振幅更大,这是如果信号由SZ效应产生所需要的。由于它是在零色散下测量的,所以偶极子不可能是由于热SZ效应引起的。我们的结果是一致的,我们从5年的WMAP数据和使用专有的集群目录较早获得的。此外,他们是强大的四极删除,证明四极泄漏的信号可以忽略不计。较低的噪音的7年WMAP也使我们能够,第一次,获得初步的经验证实我们早先的猜想,即采用的过滤翻转现实集群的KSZ效应的迹象,从而推导出的流动方向。后者在振幅和方向上与我们先前的测量一致。假设过滤确实翻转了星系团的KSZ效应的符号,这个方向也与使用星系作为较低距离示踪剂的独立工作的结果吻合得很好。我们将从公共数据中推导出的所有地图和集群模板提供给科学界,以便对我们的方法和发现进行独立测试。

英文摘要:

We present new results on the "dark flow" from a measurement of the dipole in the distribution of peculiar velocities of galaxy clusters, applying the methodology proposed and developed by us earlier. Our latest measurement is conducted using new, low-noise 7-yr WMAP data as well as an all-sky sample of X-ray selected galaxy clusters compiled exclusively from published catalogs. Our analysis of the CMB signature of the kinematic Sunyaev-Zeldovich (SZ) effect finds a statistically significant dipole at the location of galaxy clusters. The residual dipole outside the cluster regions is small, rendering our overall measurement 3-4 sigma significant. The amplitude of the dipole correlates with cluster properties, being larger for the most X-ray luminous clusters, as required if the signal is produced by the SZ effect. Since it is measured at zero monopole, the dipole can not be due to the thermal SZ effect. Our results are consistent with those obtained earlier by us from 5-yr WMAP data and using a proprietary cluster catalog. In addition, they are robust to quadrupole removal, demonstrating that quadrupole leakage contributes negligibly to the signal. The lower noise of the 7-yr WMAP also allows us, for the first time, to obtain tentative empirical confirmation of our earlier conjecture that the adopted filtering flips the sign of the KSZ effect for realistic clusters and thus of the deduced direction of the flow. The latter is consistent with our earlier measurement in both the amplitude and direction. Assuming the filtering indeed flips the sign of the KSZ effect from the clusters, the direction agrees well also with the results of independent work using galaxies as tracers at lower distances. We make all maps and cluster templates derived by us from public data available to the scientific community to allow independent tests of our method and findings.

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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