论文标题
棱镜：用于星系的辐射流体动力学模拟的非平衡，多相星际培养基
PRISM: A Non-Equilibrium, Multiphase Interstellar Medium Model for Radiation Hydrodynamics Simulations of Galaxies
论文作者
论文摘要
我们在Ramses-RTZ代码中介绍了热化学及其实现的棱镜星际介质（ISM）模型。该模型包括一个非平衡原始，金属和分子化学网络，用于115种与直接多频辐射传输结合的物种。 PRISM accurately accounts for the dominant ISM cooling and heating processes in the low-density regime (i.e. $ρ<10^5\ {\rm cm^{-3}}$), including photoheating, photoelectric heating, H$_2$ heating/cooling, cosmic-ray heating, H/He cooling, metal-line cooling, CO cooling, and dust cooling (recombination and气体碰撞）。我们通过将六个金属性的1D平衡模拟与文献中现有的1D ISM模型进行比较来验证该模型。我们将PRISM应用于高分辨率（4.5 PC）孤立的矮星系模拟，其中包括恒星形成和恒星反馈的最先进模型，以进行库存的库存，这些模型占据了银河系的每个不同气相，并了解非平衡效应的重要性。我们表明，大多数ISM气体要么接近热平衡，要么表现出轻微的冷却不稳定性，而从化学的角度来看，非均衡电子分数通常比平衡值高三倍或低三倍或低于平衡值，这会影响冷却，加热，加热和可观察的发射线。电子增强功能归因于重组滞后，而缺陷被证明是由于快速宇宙射线加热所致。棱镜模型及其与Ramses-RTZ的耦合适用于从宇宙学模拟到孤立的巨型分子云的各种天体物理场景，并且对于了解ISM物理学的变化如何影响可观察到的数量，例如金属排放线等可观察到的数量特别有用。
We introduce the PRISM interstellar medium (ISM) model for thermochemistry and its implementation in the RAMSES-RTZ code. The model includes a non-equilibrium primordial, metal, and molecular chemistry network for 115 species coupled to on-the-fly multifrequency radiation transport. PRISM accurately accounts for the dominant ISM cooling and heating processes in the low-density regime (i.e. $ρ<10^5\ {\rm cm^{-3}}$), including photoheating, photoelectric heating, H$_2$ heating/cooling, cosmic-ray heating, H/He cooling, metal-line cooling, CO cooling, and dust cooling (recombination and gas-grain collisions). We validate the model by comparing 1D equilibrium simulations across six dex in metallicity to existing 1D ISM models in the literature. We apply PRISM to high-resolution (4.5 pc) isolated dwarf galaxy simulations that include state-of-the-art models for star formation and stellar feedback to take an inventory of which cooling and heating processes dominate each different gas phase of a galaxy and to understand the importance of non-equilibrium effects. We show that most of the ISM gas is either close to thermal equilibrium or exhibits a slight cooling instability, while from a chemical perspective, the non-equilibrium electron fraction is often more than three times higher or lower than the equilibrium value, which impacts cooling, heating, and observable emission lines. Electron enhancements are attributed to recombination lags while deficits are shown to be due to rapid cosmic-ray heating. The PRISM model and its coupling to RAMSES-RTZ is applicable to a wide variety of astrophysical scenarios, from cosmological simulations to isolated giant molecular clouds, and is particularly useful for understanding how changes to ISM physics impact observable quantities such as metallic emission lines.
