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arXiv 1409.0307astro-ph.GAastro-ph.CO
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星系团尺度上的化学演化：一个难题？

Chemical Evolution on the Scale of Clusters of Galaxies: A Conundrum?

A. Renzini, S. Andreon

备注：
MNRAS, in press
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摘要：

星系团的金属含量及其与恒星含量的关系被重新审视，利用集群样本，所有四个基本参数均匀测量一致的半径内，即核心切除质量加权金属丰度加上总，恒星和ICM群众。对于总质量为$M_{500} >$ $\sim 10^{14}$ $M_{\odot}$的星系团，发现它们的铁含量与经验超新星产额的预期值之间有很好的一致性。对于相同的星团，在星团内介质（ICM）中似乎也至少有与恒星中仍然锁定的铁一样多的铁（即，ICM/Stars金属股是关于团结的）。然而，对于更大质量的星团，恒星质量分数似乎大幅下降，而没有伴随着ICM金属丰度的下降，从而产生了与核合成预期的主要紧张局势，并将金属份额膨胀到极高的值（高达$\sim 6$）。这个难题的各种可能的解决方案进行了讨论，但都被认为是天体物理学上难以置信的，或缺乏独立的观测支持。出于这个原因，我们仍然认为即使是一些最好的聚类数据也可能是错误的，尽管我们无法识别任何明显的偏差。最后，基于恒星质量-金属丰度关系的本地星系，我们估计的贡献的ICM丰富的星系作为其质量的函数，得出的结论是，即使是最庞大的星系必须失去了一个主要部分的金属，他们已经产生。

英文摘要：

The metal content of clusters of galaxies and its relation to their stellar content is revisited making use of a cluster sample for which all four basic parameters are homogeneously measured within consistent radii, namely core-excised mass-weighted metallicity plus total, stellar and ICM masses. For clusters of total mass $M_{500} >$ $\sim 10^{14}$ $M_{\odot}$ nice agreement is found between their iron content and what expected from empirical supernova yields. For the same clusters, there also appears to be at least as much iron in the intracluster medium (ICM) as there is still locked into stars (i.e., the ICM/stars metal share is about unity). However, for more massive clusters the stellar mass fraction appears to drop substantially without being accompanied by a drop in the ICM metallicity, thus generating a major tension with the nucleosynthesis expectation and inflating the metal share to extremely high values (up to $\sim 6$). Various possible solutions of this conundrum are discussed, but are all considered either astrophysically implausible, or lacking an independent observational support. For this reason we still entertain the possibility that even some of the best cluster data may be faulty, though we are not able to identify any obvious bias. Finally, based on the stellar mass-metallicity relation for local galaxies we estimate the contribution of galaxies to the ICM enrichment as a function of their mass, concluding that even the most massive galaxies must have lost a major fraction of the metals they have produced.

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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