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arXiv 0903.3066astro-ph.COastro-ph.HE
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星系团的软X射线过剩:热灯丝模型和背景星系群的强透镜

Soft X-ray excess of clusters: a thermal filament model, and the strong lensing of background galaxy groups

Richard Lieu, Max Bonamente

摘要:

本文综述了寻找宇宙学重子的观测和理论现状,并讨论了一些间接探测方法。在星系团外围暖热星系际介质(WHIM)的高密度部分--发射灯丝的背景下,研究了星系团软X射线和EUV过剩现象的热解释.我们推导出一个简单的灯丝模型,这为我们提供了一种手段,观测约束WHIM参数,特别是与集群相关的暖气体的总质量预算的软过剩表面亮度的径向轮廓。然后,我们指出了一个新的情况下,软过量发射,即。一个集群,可以强烈透镜的软X射线从背景WHIM结。如果像看起来很有可能的那样,失踪的重子大部分在星系群的WHIM晕中,那么透镜几率将相当高($\sim$ 10%)。这种方式占至少一部分的集群的软过剩也可以解释的情况下,O VII吸收红移的集群。

英文摘要:

The observational and theoretical status of the search for missing cosmological baryons is summarized, with a discussion of some indirect methods of detection. The thermal interpretation of the cluster soft X-ray and EUV excess phenomenon is examined in the context of emission filaments, which are the higher density part of the warm hot intergalactic medium (WHIM) residing at the outskirt of clusters. We derived an analytic radial profile of the soft excess surface brightness using a simple filament model, which provided us a means of observationally constraining the WHIM parameters, especially the total mass budget of warm gas associated with a cluster. We then pointed out a new scenario for soft excess emission, viz. a cluster that can strongly lens the soft X-rays from background WHIM knots. If, as seems quite likely, the missing baryons are mostly in the WHIM halos of galaxy groups, the lensing probability will be quite high ($\sim$ 10 %). This way of accounting for at least part of a cluster's soft excess may also explain the absence of O VII absorption at the redshift of the cluster.

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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