被激波加热驱离：辐射冷却对超新星遗迹中气相转变的影响
Shock-heated Away: The Impact of Radiative Cooling on Gas-Phase Transitions in Supernova Remnants
- University of Maryland（马里兰大学）
- Center for Astrophysics, Harvard & Smithsonian（哈佛-史密松天体物理中心）
- Technion - Israel Institute of Technology（以色列理工学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过受控模拟揭示辐射冷却为超新星遗迹热气体产生的关键调控因素，推导了热气体峰值质量的预测关系及蒸发效率表达式，成果可用于星系形成模拟的超新星反馈亚网格模型。
AI中文摘要：
超新星（SN）反馈通过注入能量和动量在调控星际介质（ISM）结构中发挥核心作用。超新星产生的热气体量是决定SN反馈加热ISM以及驱动其不同气相（此处定义为冷气体：$T < 10^3\\, \mathrm{K}$；暖气体：$10^3\\, \mathrm{K} < T < 2\times10^4\\, \mathrm{K}$；热气体：$T > 2\times10^4\\, \mathrm{K}$）之间质量交换效率的关键量。然而，此前的研究报告了在其他环境条件相似情况下形成的热气体量存在差异。为解决这些分歧，我们使用一系列受控模拟量化了单次SN爆炸产生的热气体量，模拟涵盖了包括均匀和湍流多相背景在内的广泛ISM环境。我们表明，辐射冷却是调控热气体产生的关键因素，冷却效率的差异可解释文献中报道的部分分歧。我们根据超新星遗迹演化过程中达到的热气体峰值质量，结合平均环境密度、初始相分布以及气体冷却效率（我们将其参数化为$10^{4.5}\\,\mathrm{K} \lesssim T \lesssim 10^{5.1}\\,\mathrm{K}$关键温度范围内的冷却时间），推导了一个简单的预测关系。最后，我们使用示踪粒子区分了冷气体和暖气体向热相的蒸发过程，并推导了具有物理依据的蒸发效率表达式。我们的结果为热气体产生和相转变提供了简单的预测关系，可纳入星系形成模拟中SN反馈的亚网格模型。
英文摘要：
Supernova (SN) feedback plays a central role in regulating the structure of the interstellar medium (ISM) through the injection of energy and momentum. The amount of hot gas produced by a supernova is a key quantity that determines how efficiently SN feedback heats the ISM and drives mass exchange between its different gas phases, here defined as cold ($T < 10^3\, \mathrm{K}$), warm ($10^3\, \mathrm{K} < T < 2\times10^4\, \mathrm{K}$), and hot ($T > 2\times10^4\, \mathrm{K}$) gas. However, previous studies have reported discrepant amounts of hot gas formed under otherwise similar ambient conditions. To resolve these disagreements, we quantify the amount of hot gas produced by individual SN explosions using a suite of controlled simulations spanning a broad range of ISM environments that include both uniform and turbulent, multiphase backgrounds. We show that radiative cooling is a key factor regulating hot-gas production, and that differences in cooling efficiency can account for some of the discrepancies reported in the literature. We derive a simple predictive relation for the peak hot-gas mass attained during the evolution of a supernova remnant in terms of the mean ambient density, the initial phase distribution, and the efficiency of gas cooling, which we parameterize as the cooling time over a key temperature range of $10^{4.5}\,\mathrm{K} \lesssim T \lesssim 10^{5.1}\,\mathrm{K}$. Finally, using tracer particles, we distinguish the evaporation of cold and warm gas into the hot phase and derive physically motivated expressions for the evaporation efficiency. Our results provide simple, predictive relations for hot-gas production and phase transitions that can be incorporated into subgrid models of SN feedback in galaxy formation simulations.
