We present the fourth of the Cholla Galactic OutfLow Simulations suite (CGOLS). Using a physically-motivated prescription for clustered supernova feedback, we successfully drive a multiphase outflow from a disk galaxy. The high resolution ($< 5\,\mathrm{pc}$) across a relatively large domain ($20\,\mathrm{kpc}$) allows us to capture the hydrodynamic mixing and dynamical interactions between the hot and cool ($T \sim 10^4\,\mathrm{K}$) phases in the outflow, which in turn leads to direct evidence of a qualitatively new mechanism for cool gas acceleration in galactic winds. We show that mixing of momentum from the hot phase to the cool phase accelerates the cool gas to $800\,\mathrm{km}\,\mathrm{s}^{-1}$ on kpc scales, with properties inconsistent with the physical models of ram pressure acceleration or with bulk cooling from the hot phase. The mixing process also affects the hot phase, modifying its radial profiles of temperature, density, and velocity from the expectations of radial supersonic flow. This mechanism provides a physical explanation for the high velocity, blue shifted, low ionization absorption lines often observed in the spectra of starburst and high redshift galaxies.

中文翻译：

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星暴驱动的银河外流的物理性质

我们展示了 Cholla Galactic OutfLow 模拟套件 (CGOLS) 的第四个套件。使用物理驱动的成簇超新星反馈处方，我们成功地驱动了盘状星系的多相外流。跨越相对较大域（$20\,\mathrm{kpc}$）的高分辨率（$< 5\,\mathrm{pc}$）使我们能够捕获热和冷（$T \sim 10^4\,\mathrm{K}$) 相流出，这反过来又直接证明了银河风中冷气体加速的新机制。我们表明，从热相到冷相的动量混合使冷气体在 kpc 尺度上加速到 $800\,\mathrm{km}\,\mathrm{s}^{-1}$，其性质与物理性质不一致。冲压压力加速模型或热相的整体冷却模型。混合过程也会影响热相，根据径向超音速流动的预期修改其径向温度、密度和速度分布。这种机制为星暴和高红移星系光谱中经常观察到的高速、蓝移、低电离吸收线提供了物理解释。