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arXiv 1602.01845astro-ph.GA
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非常宽视野的$gzK$星系巡天-- II。基于HOD模拟的$z \sim 2$恒星形成星系与其宿主晕之间的关系

The very wide-field $gzK$ galaxy survey -- II. The relationship between star-forming galaxies at $z \sim 2$ and their host haloes based upon HOD modelling

Shogo Ishikawa, Nobunari Kashikawa, Takashi Hamana, Jun Toshikawa, Masafusa Onoue

摘要:

本文给出了在$z \sim 2$上对恒星形成星系的晕占据分布(HOD)分析结果。我们获得了高质量的角度关联函数的基础上,一个大的sgzK样本,这使我们能够进行HOD分析。的平均晕质量和HOD质量参数被发现单调增加与增加$K$带的幅度,这表明更明亮的星系居住在更大规模的黑暗晕。HOD质量参数的光度依赖性被发现与本地宇宙相同;然而,在所有的星等范围内,质量都大于本地宇宙。这意味着在$z \sim 2$的星系倾向于形成比在本地宇宙中更大质量的暗晕,这一过程被称为缩小。利用扩展的Press-Schechter公式分析暗晕质量演化和暗晕中卫星星系的数量演化,发现$z \sim 4$处的暗莱曼破裂星系可以演化为$z \sim 2$处最暗的sgzKs $(22.0 < K \leq 23.0)$,并演化为局域宇宙中的类银河星系或椭圆星系。而最明亮的sgzKs $(18.0 \leq K \leq 21.0)$则可能演化成本宇宙中质量最大的系统。发现sgzKs的星晕质量比(SHMR)与模型的预测一致,除了最暗的sgzKs的SHMR小于$z \sim 2$的预测。这种差异可能归因于我们的样本仅限于恒星形成星系。

英文摘要:

We present the results of an halo occupation distribution (HOD) analysis of star-forming galaxies at $z \sim 2$. We obtained high-quality angular correlation functions based on a large sgzK sample, which enabled us to carry out the HOD analysis. The mean halo mass and the HOD mass parameters are found to increase monotonically with increasing $K$-band magnitude, suggesting that more luminous galaxies reside in more massive dark haloes. The luminosity dependence of the HOD mass parameters was found to be the same as in the local Universe; however, the masses were larger than in the local Universe over all ranges of magnitude. This implies that galaxies at $z \sim 2$ tend to form in more massive dark haloes than in the local Universe, a process known as downsizing. By analysing the dark halo mass evolution using the extended Press--Schechter formalism and the number evolution of satellite galaxies in a dark halo, we find that faint Lyman break galaxies at $z \sim 4$ could evolve into the faintest sgzKs $(22.0 < K \leq 23.0)$ at $z \sim 2$ and into the Milky-Way-like galaxies or elliptical galaxies in the local Universe, whereas the most luminous sgzKs $(18.0 \leq K \leq 21.0)$ could evolve into the most massive systems in the local Universe. The stellar-to-halo mass ratio (SHMR) of the sgzKs was found to be consistent with the prediction of the model, except that the SHMR of the faintest sgzKs was smaller than the prediction at $z \sim 2$. This discrepancy may be attributed that our samples are confined to star-forming galaxies.

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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