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arXiv 1407.7868astro-ph.CO
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比较文献中的质量(CoMaLit)-I。弱透镜效应中的偏置和散射及团簇的X射线质量估计

Comparing Masses in Literature (CoMaLit)-I. Bias and scatter in weak lensing and X-ray mass estimates of clusters

Mauro Sereno, Stefano Ettori

摘要:

在天体物理学和宇宙学中使用星系团的第一块基石是精确测定它们的质量。两个最好的直接质量估计是基于弱透镜(WL)的测定或X射线分析假设流体静力平衡(HE)。通过比较这两个质量测量样品中的丰富的集群,我们确定了固有的散射,$σ_\mathrm{WL}\sim$ 15%的WL群众和$σ_\mathrm{HE}\sim$ 25%的HE群众。不同研究组报告的WL或HE质量估计值差异高达$\sim$ 40%,这阻碍了对偏倚的某些评估。如果不考虑质量估计中的内在分散性,任何比例关系“可观测-质量”的斜率都偏向较浅的值,而比例关系的内在分散性则被高估。

英文摘要:

The first building block to use galaxy clusters in astrophysics and cosmology is the accurate determination of their mass. Two of the most well regarded direct mass estimators are based on weak lensing (WL) determinations or X-ray analyses assuming hydrostatic equilibrium (HE). By comparing these two mass measurements in samples of rich clusters, we determined the intrinsic scatters, $σ_\mathrm{WL}\sim$15 per cent for WL masses and $σ_\mathrm{HE}\sim$25 per cent for HE masses. The certain assessment of the bias is hampered by differences as large as $\sim$40 per cent in either WL or HE mass estimates reported by different groups. If the intrinsic scatter in the mass estimate is not considered, the slope of any scaling relation `observable--mass' is biased towards shallower values, whereas the intrinsic scatter of the scaling is over-estimated.

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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