Star formation histories of dwarf galaxies in the FIRE simulations: dependence on mass and Local Group environment
Star formation histories of dwarf galaxies in the FIRE simulations: dependence on mass and Local Group environment
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DOI：
10.1093/mnras/stz2507
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发表时间：
2019-03
影响因子：
4.8
通讯作者：
S. Garrison-Kimmel;A. Wetzel;P. Hopkins;R. Sanderson;R. Sanderson;K. El-Badry;A. Graus;A. Graus-A.-Gra
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文献类型：
--
作者：
S. Garrison-Kimmel;A. Wetzel;P. Hopkins;R. Sanderson;R. Sanderson;K. El-Badry;A. Graus;A. Graus-A.-Gra
本文研究了500个矮星系（恒星质量$M_ast =10^5）的星星形成历史（SFH）。10^9\，\rm {M}_\odot$）来自FIRE-2宇宙学放大模拟。我们比较了单个银河系（MW）质量星系周围的矮星系，在本星系群（LG）的环境中的矮星系，和真正的领域（即孤立的）矮星系。我们再现观察到的趋势，其中质量较高的矮星淬火后（如果在所有），无论环境。我们还确定了环境之间的差异，无论是在“卫星与中央”和“LG与个人MW与孤立的矮中央。围绕个别MW质量主机，我们恢复预期的结果从环境淬火：中央星系在“近场”有更多的扩展SFH比他们的卫星同行，前者更接近孤立的（真场）矮星（虽然近场中心仍然有点早形成）。然而，这种差异是静音LG类环境中，近场中心和卫星有类似的SFH，这类似于卫星的单MW质量主机。这种区别在M* = 106- 10^7\，\rm {M}_\odot$时最强，但在其他质量时也存在。我们的研究结果表明，成对的光环性质的LG可能会调节星星形成的矮星系，甚至超越维里半径的MW和仙女座。在比较孤立矮星系与LG中观测到的矮星系的放大模拟时需要谨慎。
We study star formation histories (SFHs) of 500 dwarf galaxies (stellar mass $M_\ast =10^5\!-\!10^9\, \rm {M}_\odot$) from FIRE-2 cosmological zoom-in simulations. We compare dwarfs around individual Milky Way (MW)-mass galaxies, dwarfs in Local Group (LG)-like environments, and true field (i.e. isolated) dwarf galaxies. We reproduce observed trends wherein higher mass dwarfs quench later (if at all), regardless of environment. We also identify differences between the environments, both in terms of ‘satellite versus central’ and ‘LG versus individual MW versus isolated dwarf central.’ Around the individual MW-mass hosts, we recover the result expected from environmental quenching: central galaxies in the ‘near field’ have more extended SFHs than their satellite counterparts, with the former more closely resemble isolated (true field) dwarfs (though near-field centrals are still somewhat earlier forming). However, this difference is muted in the LG-like environments, where both near-field centrals and satellites have similar SFHs, which resemble satellites of single MW-mass hosts. This distinction is strongest for M* = 106–$10^7\, \rm {M}_\odot$ but exists at other masses. Our results suggest that the paired halo nature of the LG may regulate star formation in dwarf galaxies even beyond the virial radii of the MW and Andromeda. Caution is needed when comparing zoom-in simulations targeting isolated dwarf galaxies against observed dwarf galaxies in the LG.