Hall drift in the stratified crusts of neutron stars
Hall drift in the stratified crusts of neutron stars
复制标题
中子星分层地壳中的霍尔漂移
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
G. Rüdiger
中科院分区：
文献类型：
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作者：
Rainer Hollerbach;G. Rüdiger
我们扩展了我们以前的中子星霍尔漂移的数值模型（Hollerbach & Rudiger 2002），以包括地壳深度的密度变化。对于纯环形场，结果与Vainshtein，Chitre和Olinto（2000）的分析模型完全一致，他们表明场将发展非常精细的结构，这将导致它在霍尔时间尺度上而不是更长的欧姆时间尺度上衰减。然而，如果我们包括极向场（Vainshtein等人没有考虑），行为是相当不同的。场仍然发展出精细的结构，但不像以前那样精细，大致按R-1/2 B标度，而不是纯环形场的R-1 B标度（其中霍尔参数R B测量欧姆时间标度与霍尔时间标度的比率）。结果，场的衰减仍然比欧姆衰减单独作用时快得多，但最终仍在欧姆时间尺度上。即使初始极向场比初始环向场弱得多（环向场的符号也起重要作用），这也是正确的。最后，我们考虑了可能的影响磁场的真实的中子星。
We extend our previous numerical model of Hall drift in neutron stars (Hollerbach & Rudiger 2002) to include variations in density across the depth of the crust. For purely toroidal fields, the results are in perfect agreement with the analytic model of Vainshtein, Chitre & Olinto (2000), who showed that the field would develop very fine structures, which would cause it to decay on the Hall time-scale rather than the much longer ohmic time-scale. However, if we include poloidal fields (which were not considered by Vainshtein et al.), the behaviour is rather different. The field still develops fine structures, but not as fine as before, scaling roughly as R -1/2 B rather than the R -1 B scaling obtained for purely toroidal fields (where the Hall parameter R B measures the ratio of the ohmic time-scale to the Hall time-scale). As a result, the field still decays considerably faster than if ohmic decay alone were acting, but ultimately still on the ohmic time-scale. This is true even if the initial poloidal field is much weaker than the initial toroidal field (with the sign of the toroidal field also playing an important role). Finally, we consider the possible implications for the magnetic fields of real neutron stars.