论文标题
在过去的10个Gyr I上变化的环境介质:物理和动力学特性
The changing circumgalactic medium over the last 10 Gyr I: physical and dynamical properties
论文作者
论文摘要
我们介绍了两组Galaxy Haloes的鹰缩放模拟的物理和动态状态的分析,一个在高红移($ z = 2-3 $),另一个处于低红移($ z = 0 $),质量为$ \ of 10^{12} M _ {\ odot} $。我们的重点是这些$ l^*$星形星系的环境介质(CGM)如何在过去10个GYR中变化。我们发现高$ z $ CGM几乎在“酷”($ t <10^5 $ k)和“热”($ t \ geq 10^5 $ k)阶段之间均等,而低$ z $ z $热CGM阶段包含$ 5 \ times $ $ $更多的质量。高$ z $ HOT CGM的金属比酷CGM多60%,而低$ z $ cool CGM的金属含有比热CGM含量高35%的金属。金属均匀分布在整个高$ z $ CGM中的热和凉爽相之间。在高$ z $的情况下,CGM的体积由热流出主导,凉爽的气体主要流入,但凉爽的金属在向外流动。在低$ z $的情况下,凉爽的金属在较大的半径上占主导地位,热金属更为普遍。低$ z $ cool CGM具有与轮换支撑相一致的切向动作,至$ 0.2 r_ {200} $,通常显示出$ r \ r \ 40 $ kpc discliel的结构。低$ z $ HOT CGM的角度动量比凉爽的CGM高几倍,而径向密度比高$ z $ HOT CGM更扁平。这项研究验证了,正如星系在宇宙时间内表现出明显的进化阶段一样,它们周围的气态光环在密度,温度和金属性的物理特征以及速度和角动量的动态特性上也会发生很大变化。
We present an analysis of the physical and dynamical states of two sets of EAGLE zoom simulations of galaxy haloes, one at high redshift ($z=2-3$) and the other at low redshift ($z=0$), with masses of $\approx 10^{12} M_{\odot}$. Our focus is how the circumgalactic medium (CGM) of these $L^*$ star-forming galaxies change over the last 10 Gyr. We find that the high-$z$ CGM is almost equally divided between the "cool" ($T<10^5$ K) and "hot" ($T\geq 10^5$ K) phases, while the low-$z$ hot CGM phase contains $5\times$ more mass. The high-$z$ hot CGM contains 60% more metals than the cool CGM, while the low-$z$ cool CGM contains 35% more metals than the hot CGM content. The metals are evenly distributed radially between the hot and cool phases throughout the high-$z$ CGM. At high $z$, the CGM volume is dominated by hot outflows, cool gas is mainly inflowing, but cool metals are flowing outward. At low $z$, the cool metals dominate the interior and the hot metals are more prevalent at larger radii. The low-$z$ cool CGM has tangential motions consistent with rotational support out to $0.2 R_{200}$, often exhibiting $r \approx 40$ kpc disc-like structures. The low-$z$ hot CGM has several times greater angular momentum than the cool CGM, and a more flattened radial density profile than the high-$z$ hot CGM. This study verifies that, just as galaxies demonstrate significant evolutionary stages over cosmic time, the gaseous haloes surrounding them also undergo considerable changes of their own both in physical characteristics of density, temperature and metallicity, and dynamic properties of velocity and angular momentum.