THE BARYON CYCLE OF DWARF GALAXIES: DARK, BURSTY, GAS-RICH POLLUTERS
THE BARYON CYCLE OF DWARF GALAXIES: DARK, BURSTY, GAS-RICH POLLUTERS
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矮星系的重子周期：黑暗、爆炸、富含气体的污染物
DOI：
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
L. Mayer
中科院分区：
文献类型：
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作者：
S. Shen;P. Madau;C. Conroy;F. Governato;L. Mayer
我们提出了一个完全宇宙学的，非常高分辨率的，ΛCDM模拟的一组七个场矮星系的今天维里质量的范围Mvir = 4.4 × 108-3.6 × 1010 M的范围。模拟包括超新星反馈的爆炸波方案，基于高气体密度阈值的恒星形成配方，金属依赖的辐射冷却，金属和热能的湍流扩散方案，以及均匀的紫外线背景。模拟的矮星的性质强烈调制的引力势阱的深度。所有三个Mvir < 109 M的晕都没有恒星，因为它们从来没有达到星星形成的密度阈值100个原子cm−3。其他四颗，Mvir > 109 M的矮矮星有蓝色，低恒星形成效率，高冷气-恒星质量比，低恒星金属丰度。它们的爆发性恒星形成历史的特征是峰值比恒星形成率超过50-100 Gyr−1，远远超出了正常的更大质量星系的范围。模拟星系的恒星年龄中位数随着晕质量的减少而减少，其中两个Mvir 102 -3 × 109 M的矮星主要是年轻的，而两个更大的系统则拥有中间和更老的人口。宇宙学上年轻的矮星被潮汐相互作用照亮，具有紧凑的形态，并且具有类似于相对静止，极度缺乏金属的矮星人口的金属丰度和冷气体分数。富含金属的星系外流产生亚太阳的有效产额，并以重元素污染星系际介质的百万秒差距大小的区域，但不足以完全熄灭恒星形成活动，并且在最暗的矮星中不存在。
We present results from a fully cosmological, very high-resolution, ΛCDM simulation of a group of seven field dwarf galaxies with present-day virial masses in the range Mvir = 4.4 × 108–3.6 × 1010 M☉. The simulation includes a blastwave scheme for supernova feedback, a star-formation recipe based on a high gas density threshold, metal-dependent radiative cooling, a scheme for the turbulent diffusion of metals and thermal energy, and a uniform UV background. The properties of the simulated dwarfs are strongly modulated by the depth of the gravitational potential well. All three halos with Mvir < 109 M☉ are devoid of stars, as they never reach the density threshold for star formation of 100 atoms cm−3. The other four, Mvir > 109 M☉ dwarfs have blue colors, low star-formation efficiencies, high cold gas-to-stellar mass ratios, and low stellar metallicities. Their bursty star-formation histories are characterized by peak specific star-formation rates in excess of 50–100 Gyr−1, far outside the realm of normal, more massive galaxies. The median stellar age of the simulated galaxies decreases with decreasing halo mass, with the two Mvir ≃ 2–3 × 109 M☉ dwarfs being predominantly young, and the two more massive systems hosting intermediate and older populations. The cosmologically young dwarfs are lit up by tidal interactions, have compact morphologies, and have metallicities and cold gas fractions similar to the relatively quiescent, extremely metal-deficient dwarf population. Metal-enriched galactic outflows produce sub-solar effective yields and pollute with heavy elements a megaparsec-size region of the intergalactic medium, but are not sufficient to completely quench star-formation activity and are absent in the faintest dwarfs.
影响因子：
4.8
作者：
C. Brook;G. Stinson;Bradley K Gibson;Bradley K Gibson;S. Shen;A. Macciò;A. Obreja;J. Wadsley;Thomas P. Quinn
通讯作者：
C. Brook;G. Stinson;Bradley K Gibson;Bradley K Gibson;S. Shen;A. Macciò;A. Obreja;J. Wadsley;Thomas P. Quinn
DOI：
10.1088/2041-8205/730/2/l13
发表时间：
2011-02
期刊：
The Astrophysical Journal Letters
影响因子：
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作者：
F. Bigiel;A. Leroy;F. Walter;E. Brinks;W. D. Blok;C. Kramer;H. Rix;A. Schruba;K. Schuster;A. Usero;H. Wiesemeyer
通讯作者：
F. Bigiel;A. Leroy;F. Walter;E. Brinks;W. D. Blok;C. Kramer;H. Rix;A. Schruba;K. Schuster;A. Usero;H. Wiesemeyer