The Local Group on FIRE: dwarf galaxy populations across a suite of hydrodynamic simulations
The Local Group on FIRE: dwarf galaxy populations across a suite of hydrodynamic simulations
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DOI：
10.1093/mnras/stz1317
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发表时间：
2018-06
影响因子：
4.8
通讯作者：
S. Garrison-Kimmel;P. Hopkins;A. Wetzel;J. Bullock;M. Boylan-Kolchin;D. Keres̆;C. Faucher-Giguère;K. El-Badry;A. Lamberts;E. Quataert;R. Sanderson
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作者：
S. Garrison-Kimmel;P. Hopkins;A. Wetzel;J. Bullock;M. Boylan-Kolchin;D. Keres̆;C. Faucher-Giguère;K. El-Badry;A. Lamberts;E. Quataert;R. Sanderson
我们提出了一套新的高分辨率流体动力学宇宙放大模拟，应用反馈在现实环境物理学的本地集团（LG）一样，孤立的银河系（MW）一样的体积（10个主机系统，重子粒子质量${\simeq } 3500\！-\！7000\，{\rm M}_\odot$）。我们研究了矮星系群的恒星质量函数、圆速度或质量分布以及速度色散。模拟结果再现了MW卫星矮星的恒星质量函数和中心密度，并预测了MW卫星矮星周围300 kpc内存在103个MW卫星矮星的质量函数和中心密度。总的来说，我们没有发现证据的经典失踪卫星或太大而不能倒（TBTF）的问题，卫星星系在我们的样本。在卫星，TBTF解决主要是由subhalo中断和整体质量损失，中央密度分布的subhaloes是次要的。对于非卫星星系，我们的类似LG的模拟预测了多达100个尚未发现的星系，距离为0.3美元！1\，\mathrm{Mpc}$来自两个主机，$M_\ast \simeq 10^{5-6}\，{\rm M}_\odot$（在Vmax为20 km s-1的晕中），尽管晕与晕之间的差异很大。我们的模拟没有产生一个紧凑的，重子主导的，高密度的矮椭圆型星系（在$r\lt 1\，$ kpc时Vcirc为35 km s−1），其中六个可能出现在LG中（但没有出现在MW中）。因此，它可能仍然是一个挑战，以再现侏儒人口的全部多样性，包括最高和最低密度的系统。
We present a new set of high-resolution hydrodynamic cosmological zoom-in simulations that apply the Feedback In Realistic Environments physics to both Local Group (LG)-like and isolated Milky Way (MW)-like volumes (10 host systems in total with a baryonic particle mass ${\simeq } 3500\!-\!7000\,{\rm M}_\odot$). We study the stellar mass functions, circular velocity or mass profiles, and velocity dispersions of the dwarf galaxy populations. The simulations reproduce the stellar mass function and central densities of MW satellite dwarfs for $M_\ast \ge 10^{5.5}\,{\rm M}_\odot$ and predict the existence of ∼3 unidentified galaxies with $M_\ast \sim 10^5\,{\rm M}_\odot$ within 300 kpc of the MW. Overall, we find no evidence for the classical missing satellites or too-big-to-fail (TBTF) problems for satellite galaxies in our sample. Among the satellites, TBTF is resolved primarily by subhalo disruption and overall mass-loss; central density profiles of subhaloes are of secondary importance. For non-satellite galaxies, our LG-like simulations predict as many as ∼10 as-of-yet unseen galaxies at distances $0.3\!-\!1\, \mathrm{Mpc}$ from both hosts, with $M_\ast \simeq 10^{5-6}\,{\rm M}_\odot$ (in haloes with Vmax ∼ 20 km s−1), albeit with large halo-to-halo variance. None of our simulations produces a compact, baryon-dominated, high-density dwarf elliptical-type galaxy (with Vcirc ≳ 35 km s−1 at $r\lt 1\,$ kpc), of which six may appear in the LG (but none in the MW). It may therefore remain a challenge to reproduce the full diversity of the dwarf population, including both the highest and lowest density systems.