论文标题
带有UV辐射转移的多相星际介质的光化学和加热/冷却，用于磁性流血动力学模拟
Photochemistry and Heating/Cooling of the Multiphase Interstellar Medium with UV Radiative Transfer for Magnetohydrodynamic Simulations
论文作者
论文摘要
我们提出了一种有效的加热/冷却方法，再加上化学和紫外线（UV）辐射转移，可以应用于星际培养基（ISM）的数值模拟。我们遵循氢种（H $ _2 $，H，H $^+$）的时间依赖性的演变，假设碳/氧（C，C $^+$，CO，O $ $^+$）在形成造成平衡中，鉴于非稳态的氢丰度，并包括基本的供热/冷却过程，以捕获所有ISMMMMMMMMMMMMMMEMMMENSMMENMENSMIND。来自离散点源的紫外线辐射和弥漫背景通过自适应射线跟踪和六射线近似，允许h $ _2 $自我屏蔽；还包括宇宙射线（CR）加热和电离。为了验证我们的方法并证明了它们在一系列密度，金属性和辐射场中的应用，我们进行了一系列测试，包括热压密度与密度的平衡曲线，照片分解区域中的化学和热结构，H I-TO-HO-H $ _2 $过渡，以及H II区域的扩展以及HII Remnova remnova remnava and radiative superiative superiative supernova remnants。对于ISM物理的许多方面，仔细治疗光化学和CR电离至关重要，包括识别冷和温暖中性相共存的热压。我们警告说，在银河形成模拟中使用的许多当前加热和冷却处理不会重现中性ISM中正确的热压和电离分数。我们的新模型在MHD代码Athena中实现，并在Tigress模拟框架中纳入，用于在各种环境中研究星形成ISM。
We present an efficient heating/cooling method coupled with chemistry and ultraviolet (UV) radiative transfer, which can be applied to numerical simulations of the interstellar medium (ISM). We follow the time-dependent evolution of hydrogen species (H$_2$, H, H$^+$), assume carbon/oxygen species (C, C$^+$, CO, O, and O$^+$) are in formation-destruction balance given the non-steady hydrogen abundances, and include essential heating/cooling processes needed to capture thermodynamics of all ISM phases. UV radiation from discrete point sources and the diffuse background is followed through adaptive ray tracing and a six-ray approximation, respectively, allowing for H$_2$ self-shielding; cosmic ray (CR) heating and ionization are also included. To validate our methods and demonstrate their application for a range of density, metallicity, and radiation field, we conduct a series of tests, including the equilibrium curves of thermal pressure vs. density, the chemical and thermal structure in photo-dissociation regions, H I-to-H$_2$ transitions, and the expansion of H II regions and radiative supernova remnants. Careful treatment of photochemistry and CR ionization is essential for many aspects of ISM physics, including identifying the thermal pressure at which cold and warm neutral phases co-exist. We caution that many current heating and cooling treatments used in galaxy formation simulations do not reproduce the correct thermal pressure and ionization fraction in the neutral ISM. Our new model is implemented in the MHD code Athena and incorporated in the TIGRESS simulation framework, for use in studying the star-forming ISM in a wide range of environments.
