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arXiv 0810.2537astro-ph
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模拟高红移下的暗晕:合并率、计数和类型

Simulating Subhalos at High Redshift: Merger Rates, Counts, and Types

Andrew R. Wetzel, J. D. Cohn, Martin White

摘要:

银河系被认为与模拟的暗物质暗晕一一对应。我们使用高分辨率的N体模拟宇宙学体积计算统计性质的subhalo(星系)主要合并在高红移(z=0.6-5)。我们测量了星系合并率的演化,发现它比z>2.5的暗物质宿主晕的合并率要浅得多,但大致与z<1.6的晕的合并率平行。我们还跟踪了各个星系的详细合并历史,并测量了每个晕或次晕多次合并的可能性。我们详细研究了卫星合并的统计数据:所有最近合并的星系中有15%-35%是卫星星系,卫星星系最近发生重大合并的可能性是中心星系的两倍。最后,我们展示了如何不同的演变的合并率的晕和星系导致每个晕的平均卫星占用的演变,注意到,对于一个固定的晕质量,卫星晕占用峰值在z~2.5。

英文摘要:

Galaxies are believed to be in one-to-one correspondence with simulated dark matter subhalos. We use high-resolution N-body simulations of cosmological volumes to calculate the statistical properties of subhalo (galaxy) major mergers at high redshift (z=0.6-5). We measure the evolution of the galaxy merger rate, finding that it is much shallower than the merger rate of dark matter host halos at z>2.5, but roughly parallels that of halos at z<1.6. We also track the detailed merger histories of individual galaxies and measure the likelihood of multiple mergers per halo or subhalo. We examine satellite merger statistics in detail: 15%-35% of all recently merged galaxies are satellites and satellites are twice as likely as centrals to have had a recent major merger. Finally, we show how the differing evolution of the merger rates of halos and galaxies leads to the evolution of the average satellite occupation per halo, noting that for a fixed halo mass, the satellite halo occupation peaks at z~2.5.

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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