Star formation and stellar mass assembly in dark matter haloes: from giants to dwarfs
Star formation and stellar mass assembly in dark matter haloes: from giants to dwarfs
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DOI：
10.1093/mnras/stv667
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发表时间：
2014-06
影响因子：
4.8
通讯作者：
Zhankui Lu;H. Mo;Yu Lu;N. Katz;M. Weinberg;F. V. D. Bosch;Xiaohu Yang
中科院分区：
文献类型：
--
作者：
Zhankui Lu;H. Mo;Yu Lu;N. Katz;M. Weinberg;F. V. D. Bosch;Xiaohu Yang
Lu et al.（2014）的经验模型用最近的数据进行了更新，并用于研究星系星星的形成和组装历史。在z > 2时，预测的星系恒星质量函数是陡峭的，大量的星星形成是由低质量的晕所承载的，而这些晕在目前的观测中可能会被错过。星团中心的大多数恒星形成于z2之前，但聚集的时间要晚得多。银河系质量星系自z 2以来一直在进行星星的形成而没有显著的合并，因此没有由主要合并产生的显著（经典）凸起。在大质量的星团中，恒星被束缚在星系中，分散在晕中，形成了一个古老的、具有太阳金属丰度的同质种群。相比之下，在银河系的质量系统中，这两个组成部分形成了两个不同的群体，晕星年龄更大，金属含量也更少，只有三分之一。在晕中的矮星系Mh 2，其次是一个几乎恒定的星星形成率后，z = 1。早期爆发留下了一个重要的古老的恒星群体，分布在球状体。
The empirical model of Lu et al. (2014) is updated with recent data and used to study galaxy star formation and assembly histories. At z > 2, the predicted galaxy stellar mass functions are steep, and a signicant amount of star formation is hosted by low-mass haloes that may be missed in current observations. Most of the stars in cluster centrals formed earlier than z 2 but have been assembled much later. Milky Way mass galaxies have had on-going star formation without signicant mergers since z 2, and are thus free of signicant (classic) bulges produced by major mergers. In massive clusters, stars bound in galaxies and scattered in the halo form a homogeneous population that is old and with solar metallicity. In contrast, in Milky Way mass systems the two components form two distinct populations, with halo stars being older and poorer in metals by a factor of 3. Dwarf galaxies in haloes with Mh 2, followed by a nearly constant star formation rate after z = 1. The early burst leaves a signicant old stellar population that is distributed in spheroids.