Conditions for fast magnetic reconnection in astrophysical plasmas
Conditions for fast magnetic reconnection in astrophysical plasmas
复制标题
天体物理等离子体中快速磁重联的条件
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
H Germany
中科院分区：
文献类型：
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作者：
M. Hanasz;H. C. F. Astronomy;Nicholas Copernicus University;Poland;U. Observatory;M. University;H Germany
我们根据Rogers等人（2001）最近的研究结果，研究了天体物理等离子体中快速磁重联的有利环境。考虑到存在一个具有反平行磁场线的临界磁场结构，我们的分析表明，快速重联的一个必要条件是热压力与磁场压力之比应显著大于2 me=mp（电子质量与质子质量之比的两倍）。通过几个例子（如星际介质的不同成分，星系间介质，活跃的星系核和喷流），我们表明，在几乎所有的天体物理等离子体中，磁重联进行得很快，即与电阻率无关，阿尔芬速度的几个百分点。只有在中子星和白矮星等特殊情况下才小于2me=mp。
We investigate favourable circumstances for fast magnetic reconnection in astrophysical plasmas based on recent results by Rogers et al. (2001). Given that a critical magnetic field structure with antiparallel field lines exists, our analysis demonstrates that a sucient condition for fast reconnection is that the ratio of the thermal pressure to the magnetic field pressure should be significantly larger than 2 me=mp (twice the ratio of electron mass to proton mass). Using several examples (like the dierent components of the interstellar medium, the intergalactic medium, active galactic nuclei and jets) we show that in almost all astrophysical plasmas, magnetic reconnection proceeds fast i.e. independent of the resistivity, with a few percent of the Alfven speed. Only for special cases like neutron stars and white dwarfs is smaller than 2me=mp.