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arXiv 1209.4080astro-ph.COastro-ph.GA
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朝向H2356-309的星系群和星系中的温热气体

Warm-hot gas in groups and galaxies toward H2356-309

Rik J. Williams, John S. Mulchaey, Juna A. Kollmeier

摘要:

本文详细分析了类星体H2356-309光谱中三个X射线吸收线系统周围的星系和星系群分布。先前的研究将这些吸收体与已知的大规模星系结构(即,壁和细丝)沿着视线。这样的吸收线通常跟踪10^{5-7} K气体,可能是难以捉摸的温暖-热星系际介质(WHIM)的证据,该介质被认为是大部分低红移“失踪重子”的藏身之处;或者,它们可能与单个星系或细丝中的星系群有关。在这里,我们结合现有的星系调查数据与新的,多对象麦哲伦光谱研究每个吸收器附近的详细星系分布。所有这三个吸收系统都在附近星系和/或星系团的投射维里半径内,因此可能出现在这些维里化结构中,而不是(或除了)WHIM。然而,我们发现没有额外的星系附近的第四个“空”吸收最近发现的光谱,这表明该系统可能确实跟踪气体与任何个人的晕。虽然已知系统的数量仍然很少,但空间巧合表明,一些X射线吸收体位于星系和/或星系群环境中,尽管其他人仍然可以追踪模拟预测的大规模非线性WHIM气体。

英文摘要:

We present a detailed analysis of the galaxy and group distributions around three reported X-ray absorption line systems in the spectrum of the quasar H2356-309. Previous studies associated these absorbers with known large-scale galaxy structures (i.e., walls and filaments) along the line of sight. Such absorption lines typically trace 10^{5-7} K gas, and may be evidence of the elusive warm-hot intergalactic medium (WHIM) thought to harbor the bulk of the low-redshift "missing baryons;" alternatively, they may be linked to individual galaxies or groups in the filaments. Here we combine existing galaxy survey data with new, multi-object Magellan spectroscopy to investigate the detailed galaxy distribution near each absorber. All of these three absorption systems are within the projected virial radii of nearby galaxies and/or groups, and could therefore arise in these virialized structures rather than (or in addition to) the WHIM. However, we find no additional galaxies near a fourth "void" absorber recently found in the spectrum, suggesting that this system may indeed trace gas unassociated with any individual halo. Though the number of known systems is still small, spatial coincidences suggest that some X-ray absorbers lie in galaxy and/or group environments, though others could still trace the large-scale filamentary WHIM gas predicted by simulations.

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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