Fossil records of cosmic reionization in galactic stellar halos

被引:15
作者
Bekki, K [1 ]
Chiba, M
机构
[1] Univ New S Wales, Sch Phys, Sydney, NSW 2052, Australia
[2] Tohoku Univ, Astron Inst, Sendai, Miyagi 9808578, Japan
基金
澳大利亚研究理事会;
关键词
galaxies : evolution; galaxies : stellar content; Galaxy : halo;
D O I
10.1086/431224
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Galactic stellar halos have long been considered to contain fossil information on the early dynamical and chemical evolution of galaxies. We propose that the surface brightness distributions of old stellar halos contain the influence of reionization on early formation histories of galaxies. By assuming that reionization significantly suppresses star formation in small subgalactic clumps virialized after reionization redshift (z(reion)), we first numerically investigate how the structural and kinematical properties of stellar halos that formed from the merging of these subgalactic clumps depend on. We then discuss what observable properties of galactic stellar halos z(reion) offer us; we also discuss the fossil records of reionization influence on hierarchical formation of halos based on the current results of numerical simulations. We specifically suggest that both the half-light radius of stellar halos and the slope of their surface brightness profile contain useful information regarding the times in which star formation in subgalactic clumps were significantly influenced by reionization. By using the simulated surface brightness distributions of galactic stellar halos for models with different, we also discuss how wide-field z(reion) imaging studies of extragalactic halos will help us to elucidate the epoch of cosmic reionization.
引用
收藏
页码:L107 / L110
页数:4
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