NIHAO-LG: The uniqueness of local group dwarf galaxies
NIHAO-LG: The uniqueness of local group dwarf galaxies
复制标题
NIHAO-LG：本星系群的独特性
DOI：
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发表时间：
2021
影响因子：
4.8
通讯作者：
C. Stone
中科院分区：
文献类型：
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作者：
Nikhil Arora;A. Macciò;S. Courteau;T. Buck;N. Libeskind;J. Sorce;C. Brook;Y. Hoffman;G. Yepes;E. Carlesi;C. Stone
最近对本星系群矮星系的观测和理论研究突出了它们独特的星星形成历史、恒星金属丰度、气体含量和运动学。我们调查这些功能的共性，通过比较约束LG和场中心矮晕模拟NIHAO项目。我们用NIHAO流体动力学方法模拟了MW和M31沿着100颗矮星的演化过程，揭示了气体总质量和恒星性质（速度色散、演化历史等）。与场系统相似。然而，相对于场星系，LG矮星有更多的冷气体在其中心部分和更多的富含金属的气体在晕中产生的相互作用与其他矮星生活在一个高密度的环境，如LG。有趣的是，大规模的MW/M31类似物对LG矮星的金属丰度演化的直接影响是最小的，LG矮星吸积高金属丰度气体主要来自其他矮星在晚的时候。我们还测试了金属扩散对LG矮星化学演化的影响，发现它不影响LG矮星的恒星或气体含量。我们的模拟表明，LG矮星的恒星成分为星系形成测试和比较提供了一个独特而公正的本地实验室，特别是针对宇宙中的整体矮星人口。
Recent observational and theoretical studies of the Local Group (LG) dwarf galaxies have highlighted their unique star formation history, stellar metallicity, gas content, and kinematics. We investigate the commonality of these features by comparing constrained LG and field central dwarf halo simulations in the NIHAO project. Our simulations, performed with NIHAO-like hydrodynamics which track the evolution of the MW and M31 along with ∼100 dwarfs in the Local Group, reveal the total gas mass and stellar properties (velocity dispersion, evolution history, etc.) of present-day LG dwarfs to be similar to field systems. However, relative to field galaxies, LG dwarfs have more cold gas in their central parts and more metal-rich gas in the halo stemming from interactions with other dwarfs living in a high density environment like the LG. Interestingly, the direct impact of massive MW/M31 analogues on the metallicity evolution of LG dwarfs is minimal; LG dwarfs accrete high metallicity gas mostly from other dwarfs at late times. We have also tested for the impact of metal diffusion on the chemical evolution of LG dwarfs, and found that it does not affect the stellar or gaseous content of LG dwarfs. Our simulations suggest that the stellar components of LG dwarfs offer a unique and unbiased local laboratory for galaxy formation tests and comparisons, especially against the overall dwarf population in the Universe.