The partition of irreversible heating between ions and electrons in compressively driven (but subsonic) collisionless turbulence is investigated by means of nonlinear hybrid gyrokinetic simulations. We derive a prescription for the ion-to-electron heating ratio $Q_i/Q_e$ as a function of the compressive-to-Alfvénic driving power ratio $P_{\text{compr}}/P_{\mathrm{AW}}$, of the ratio of ion thermal pressure to magnetic pressure ${\beta }_i$, and of the ratio of ion-to-electron background temperatures $T_i/T_e$. It is shown that $Q_i/Q_e$ is an increasing function of $P_{\text{compr}}/P_{\mathrm{AW}}$. When the compressive driving is sufficiently large, $Q_i/Q_e$ approaches $\simeq P_{\text{compr}}/P_{\mathrm{AW}}$. This indicates that, in turbulence with large compressive fluctuations, the partition of heating is decided at the injection scales, rather than at kinetic scales. Analysis of phase-space spectra shows that the energy transfer from inertial-range compressive fluctuations to sub-Larmor-scale kinetic Alfvén waves is absent for both low and high ${\beta }_i$, meaning that the compressive driving is directly connected to the ion-entropy fluctuations, which are converted into ion thermal energy. This result suggests that preferential electron heating is a very special case requiring low ${\beta }_i$ and no, or weak, compressive driving. Our heating prescription has wide-ranging applications, including to the solar wind and to hot accretion disks such as M87 and Sgr A*.

中文翻译：

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压缩驱动的天体动力回旋湍流中的离子与电子加热

通过非线性混合动力动力学模拟研究了压缩驱动（但亚音速）无碰撞湍流中离子与电子之间不可逆加热的分配。我们推导了离子与电子加热比的规定${问}_{\mathrm{一世}}/{问}_{Ë}$ 与Alfvénic压缩比的函数关系 $P_{\text{电脑}}/P_{\mathrm{AW}}$，离子热压与磁压之比 ${\beta }_{\mathrm{一世}}$，以及离子与电子背景温度之比 ${Ť}_{\mathrm{一世}}/{Ť}_{Ë}$。结果表明${问}_{\mathrm{一世}}/{问}_{Ë}$ 是...的增加功能 $P_{\text{电脑}}/P_{\mathrm{AW}}$。当压缩驱动足够大时，${问}_{\mathrm{一世}}/{问}_{Ë}$ 方法 $\simeq P_{\text{电脑}}/P_{\mathrm{AW}}$。这表明，在具有大的压缩波动的湍流中，加热的分配是在注入尺度而不是动力学尺度决定的。对相空间谱的分析表明，无论是低还是高，都没有从惯性范围的压缩涨落到亚Larmor级动力学Alfvén波的能量转移${\beta }_{\mathrm{一世}}$，意味着压缩驱动与离子熵涨落直接相关，离子涨落被转换为离子热能。该结果表明，优先电子加热是一种非常低的要求${\beta }_{\mathrm{一世}}$而且没有或没有压缩驱动。我们的加热处方具有广泛的应用，包括太阳风和热吸积盘，例如M87和Sgr A *。