The physical nature of circumgalactic medium absorbers in Simba
The physical nature of circumgalactic medium absorbers in Simba
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辛巴环河介质吸收体的物理性质
DOI：
10.1093/mnras/stad025
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发表时间：
2023
影响因子：
4.8
通讯作者：
Appleby S
中科院分区：
文献类型：
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作者：
Appleby S
在Simbacosmological模拟中，我们研究了低红移环星系介质（CGM）的性质，在碰撞参数Sr_（？）≤ 1.25r ~（200）时，在恒星质量仓（$\mbox{$）中，星系周围的紫外吸收线跟踪了恒星形成、绿色谷和淬灭星系。我们生成的合成光谱为喜，MIPH，CII，SiIII，CIV，和OVI，适合福格特配置文件，以获得线的属性，并估计密度，温度和金属的吸收气体。我们发现，CGM吸收剂是最丰富的恒星形成星系周围的$\mbox{$，而丰富的绿色谷星系表现出类似的行为，淬火星系，这表明CGM“淬火”之前，星星形成停止。高吸收气体存在于广泛的宇宙相（凝聚气体，扩散气体，热晕气体和温热星系际介质（WHIM））中，而基本上所有低电离金属吸收都来自凝聚气体。吸卵器在热晕气体和WHIM之间分开。碰撞电离的CGM吸收体的分数是CivandOvi，取决于恒星质量和碰撞参数。通常，每种离子的最高柱密度吸收特征来自致密气体。卫星气体定义为10 r 1/2，μ m范围内的气体，对总的Hi吸收有贡献，但对Mgii吸收没有贡献，来自卫星气体的比例随离子激发能量的增加而减少。
We study the nature of the low-redshift circumgalactic medium (CGM) in theSimbacosmological simulations as traced by ultraviolet absorption lines around galaxies in bins of stellar mass ($\mbox{$) for star-forming, green valley and quenched galaxies at impact parametersr⊥≤ 1.25r200. We generate synthetic spectra for Hi, Mgii, Cii, Siiii, Civ, and Ovi, fit Voigt profiles to obtain line properties, and estimate the density, temperature, and metallicity of the absorbing gas. We find that CGM absorbers are most abundant around star-forming galaxies with $\mbox{$, while the abundance of green valley galaxies show similar behaviour to those of quenched galaxies, suggesting that the CGM ‘quenches’ before star formation ceases. Hiabsorbing gas exists across a broad range of cosmic phases [condensed gas, diffuse gas, hot halo gas, and Warm-Hot Intergalactic Medium (WHIM)], while essentially all low ionization metal absorption arises from condensed gas. Oviabsorbers are split between hot halo gas and the WHIM. The fraction of collisionally ionized CGM absorbers isfor Civandfor Ovi, depending on stellar mass and impact parameter. In general, the highest column density absorption features for each ion arise from dense gas. Satellite gas, defined as that within 10r1/2,⋆, contributesof overall Hiabsorption butof Mgiiabsorption, with the fraction from satellites decreasing with increasing ion excitation energy.