Modelling interaction of relativistic and non-relativistic winds in binary system PSR B1259-63/SS2883 - II. Impact of magnetization and anisotropy of the pulsar wind
Modelling interaction of relativistic and non-relativistic winds in binary system PSR B1259-63/SS2883 - II. Impact of magnetization and anisotropy of the pulsar wind
复制标题
模拟二元系统 PSR B1259-63/SS2883 中相对论性风和非相对论性风的相互作用 - II。
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
F. Aharonian
中科院分区：
文献类型：
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作者：
S. Bogovalov;D. Khangulyan;A. V. Koldoba;G. V. Ustyugova;F. Aharonian
本文数值研究了双星系统中磁化各向异性脉冲星风与其周围环境碰撞产生的流的性质。我们将磁场和风各向异性的影响与Bogovalov等人（2008）详细研究的各向同性风的纯流体动力学（HD）相互作用的基准情况进行了比较。我们在轴对称近似下考虑相互作用，即假设脉冲星自转轴沿着脉冲星与光学星星之间的直线，忽略与脉冲星轨道有关的影响。磁场的影响进行了研究的情况下，弱磁化（磁化参数$西格玛<0.1$），这是与传统的模型的脉冲星风。假设非磁化脉冲星风中的动能通量是强各向异性的，在脉冲星旋转轴上的最小值和垂直方向上的最大值，与脉冲星风的各向异性的影响进行建模。我们表明，虽然这两个考虑的影响改变了终止脉冲星风所占据的区域的形状，它们的影响似乎是小的。特别是，对于低于0.1的脉冲星风的磁化，磁场压力保持远低于等离子体压力在冲击后区域。因此，在脉冲星与恒星风环境相互作用的情况下（与plerions的情况相反，即脉冲星与星际介质的相互作用，当磁场独立于风的磁化变得动态重要时），HD方法代表了数值模拟的可行近似。
In this paper, we present a numerical study of the properties of the flow produced by the collision of a magnetized anisotropic pulsar wind with its environment in binary system. We compare the impact of both the magnetic field and the wind anisotropy to the benchmark case of a purely hydrodynamical (HD) interaction of isotropic winds, which has been studied in detail by Bogovalov et al. (2008). We consider the interaction in axisymmetric approximation, i.e. the pulsar rotation axis is assumed to be oriented along the line between the pulsar and the optical star and the effects related to the pulsar orbiting are neglected. The impact of the magnetic field is studied for the case of weak magnetization (with magnetization parameter $sigma<0.1$), which is consistent with conventional models of pulsar winds. The effects related to anisotropy in pulsar winds are modeled assuming that the kinetic energy flux in a non-magnetized pulsar wind is strongly anisotropic, with the minimum at the pulsar rotation axis and the maximum in the perpendicular direction. We show that, although both considered effects change the shape of the region occupied by the terminated pulsar wind, their impact appears to be small. In particular, for the magnetization of the pulsar wind below 0.1, the magnetic field pressure remains well below the plasma pressure in the post-shock region. Thus, in the case of interaction of a pulsar with the stellar wind environment (opposite to the case of plerions, i.e. the pulsar interaction with the interstellar medium, when the magnetic field becomes dynamically important independently on the wind magnetization) the HD approach represents a feasible approximation for numerical modelling.