论文标题
多相银河风的模拟观察结果
Simulated Observations of Multiphase Galactic Winds
论文作者
论文摘要
超新星驱动的银河风是气体的多相流，通常观察到在星系中恒星形成区域以一系列速度流动。在这项研究中，我们使用以流体动力学代码CHOLLA建模的多相银河风的高分辨率3D模拟来研究数值研究与观测之间的联系。 Using a simulated interaction between a hot $T\sim 10^{7}\,\rm K$ supernova-driven wind and a cool $T\sim 10^{4}\,\rm K$ cloud of interstellar material, we create mock observables, including the optical depth and covering fraction of six commonly observed ions (Si II, C II, Si IV, C IV, N V, and O vi）作为气速的函数。我们将模拟观察物与文献中银河风的调查进行了比较，与低离子的速度和剖面有很好的一致性。然后，我们计算观测技术后的光学深度和覆盖分数的“经验”值，并将它们与直接从仿真数据计算出的值进行比较。我们发现，经验计算的值倾向于低估具有较高光学深度离子的$τ$的“真”值，并且相对于模拟数据，对于具有低光学深度的离子，高估了$τ$的“真”值。
Supernova-driven galactic winds are multiphase streams of gas that are often observed flowing at a range of velocities out of star-forming regions in galaxies. In this study, we use high resolution 3D simulations of multiphase galactic winds modeled with the hydrodynamics code Cholla to investigate the connection between numerical studies and observations. Using a simulated interaction between a hot $T\sim 10^{7}\,\rm K$ supernova-driven wind and a cool $T\sim 10^{4}\,\rm K$ cloud of interstellar material, we create mock observables, including the optical depth and covering fraction of six commonly observed ions (Si II, C II, Si IV, C IV, N V, and O VI) as a function of gas velocity. We compare our mock observables to surveys of galactic winds in the literature, finding good agreement with velocities and profiles of the low ions. We then compute "empirical" values for the optical depth and covering fraction following observational techniques, and compare them to the values calculated directly from the simulation data. We find that the empirically computed values tend to underestimate the "true" value of $τ$ for ions with high optical depth, and overestimate the "true" value of $τ$ for ions with low optical depth, relative to the simulated data.
