在恩佐（FOGGIE）中计算出气体和星系晕V：维里温度不能描述维里化星系晕中的气体
Figuring Out Gas & Galaxies In Enzo (FOGGIE) V: The Virial Temperature Does Not Describe Gas in a Virialized Galaxy Halo
摘要：
星系晕维里温度的经典定义排除了对晕能量分配的基本贡献：非热气体运动的动能。使用模拟的低红移，$\sim L^*$星系从FOGGIE项目（Figuring Out Gas & Galerkin In Enzo），优化解决低密度气体，我们表明，非热运动的动能大致等于热运动的能量。模拟的雾晕具有$\sim 2\times$低于预期的体温度从一个经典的维里平衡，由于显着的非热动能，正式排除在定义的$T_\mathrm{vir}$。我们推导出一个修改后的维里温度显式包括非热气体运动，提供了一个更准确的描述气体温度模拟晕维里平衡。恒星反馈的强烈爆发驱动模拟的FOGGIE晕的维里平衡，但即使在维里平衡的晕气体不能准确地描述的标准维里温度。与标准维里温度相比，较冷的修改维里温度意味着对晕圈气体的其他影响：（i）热气体压力较低，（ii）辐射冷却更有效，（iii）追踪维里温度的O-VI吸收气体可能在质量比预期更高的晕中普遍存在，（iv）根据X射线表面亮度轮廓估计的气体质量可能不正确，湍流运动对星系晕的能量平衡有重要贡献。
英文摘要：
The classical definition of the virial temperature of a galaxy halo excludes a fundamental contribution to the energy partition of the halo: the kinetic energy of non-thermal gas motions. Using simulations of low-redshift, $\sim L^*$ galaxies from the FOGGIE project (Figuring Out Gas & Galaxies In Enzo) that are optimized to resolve low-density gas, we show that the kinetic energy of non-thermal motions is roughly equal to the energy of thermal motions. The simulated FOGGIE halos have $\sim 2\times$ lower bulk temperatures than expected from a classical virial equilibrium, owing to significant non-thermal kinetic energy that is formally excluded from the definition of $T_\mathrm{vir}$. We derive a modified virial temperature explicitly including non-thermal gas motions that provides a more accurate description of gas temperatures for simulated halos in virial equilibrium. Strong bursts of stellar feedback drive the simulated FOGGIE halos out of virial equilibrium, but the halo gas cannot be accurately described by the standard virial temperature even when in virial equilibrium. Compared to the standard virial temperature, the cooler modified virial temperature implies other effects on halo gas: (i) the thermal gas pressure is lower, (ii) radiative cooling is more efficient, (iii) O VI absorbing gas that traces the virial temperature may be prevalent in halos of a higher mass than expected, (iv) gas mass estimates from X-ray surface brightness profiles may be incorrect, and (v) turbulent motions make an important contribution to the energy balance of a galaxy halo.
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