Electron and Proton Heating in Transrelativistic Guide Field Reconnection
Electron and Proton Heating in Transrelativistic Guide Field Reconnection
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DOI：
10.3847/1538-4357/ab03d7
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发表时间：
2019-01
期刊：
影响因子：
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通讯作者：
M. Rowan;L. Sironi;R. Narayan
中科院分区：
文献类型：
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作者：
M. Rowan;L. Sironi;R. Narayan
在低光度吸积流中的等离子体，例如在我们银河系中心的M87或Sgr A* 中心的黑洞周围的等离子体，预计是无碰撞的，并且具有两种温度，质子比电子热。在这里，粒子加热预计将被控制的磁重联在transrelativistic制度，其中的磁化是磁能密度等离子体焓密度的比率。使用大规模的2D粒子在细胞中的模拟，我们探索一个基准如何耗散的磁能是电子和质子之间的分配作为（质子热压力磁压力的比率）的函数和强度的引导场垂直于反向场B0。在较低的温度下，我们发现每个粒子的初始磁能转化为电子不可逆热的比例几乎与温度无关，而质子的加热随着温度的升高而减少。因此，对于大的，电子接收绝大多数的不可逆粒子加热（93%）。这与反平行的情况有很大的不同，在反平行的情况下，不可逆的电子加热只占总粒子加热的2.18%（Rowan等人）。在，当两种物质开始时已经相对热（对于我们的基准），电子和质子各自接收到不可逆粒子加热的50%，而不管引导场强度如何。我们的研究结果提供了重要的见解等离子体物理的电子和质子加热的超大质量黑洞周围的热吸积流。
The plasma in low-luminosity accretion flows, such as the one around the black hole at the center of M87 or Sgr A* at our Galactic Center, is expected to be collisioness and of two temperatures, with protons hotter than electrons. Here, particle heating is expected to be controlled by magnetic reconnection in the transrelativistic regime , where the magnetization is the ratio of magnetic energy density to plasma enthalpy density. Using large-scale 2D particle-in-cell simulations, we explore for a fiducial how the dissipated magnetic energy is partitioned between electrons and protons as a function of (the ratio of proton thermal pressure to magnetic pressure) and of the strength of a guide field perpendicular to the reversing field B0. At low , we find that the fraction of initial magnetic energy per particle converted into electron irreversible heat is nearly independent of , whereas protons are heated much less with increasing . As a result, for large , electrons receive the overwhelming majority of irreversible particle heating (∼93% for ). This is significantly different than the antiparallel case , in which irreversible electron heating accounts for only ∼18% of the total particle heating (Rowan et al. ). At , when both species start already relativistically hot (for our fiducial ), electrons and protons each receive ∼50% of the irreversible particle heating, regardless of the guide field strength. Our results provide important insights into the plasma physics of electron and proton heating in hot accretion flows around supermassive black holes.