MHD Simulation of Comets: The Plasma Environment of Comet Hale-Bopp
MHD Simulation of Comets: The Plasma Environment of Comet Hale-Bopp
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彗星的 MHD 模拟：海尔-波普彗星的等离子体环境
DOI：
10.1023/a:1006289418660
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
K. Powell
中科院分区：
文献类型：
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作者：
T. Gombosi;K. Hansen;D. Dezeeuw;M. Combi;K. Powell
本文给出了海尔-波普彗星膨胀大气与磁化太阳风相互作用的MHD模拟结果。在上游边界处，一个超声速和超声速的太阳风进入了位于核上游2500万公里处的模拟箱。太阳风不断地装载着来自彗核的彗星离子。该模型考虑了光电离、复合和离子中性摩擦阻力的影响。利用muscl型迎风数值技术MAUS-MHD （multi - scale Adaptive upwind Scheme for MHD）在自适应改进的非结构化笛卡尔网格上求解控制方程。将自适应细化与muscl方案相结合，可以对整个彗星大气进行建模，同时仍然可以解决彗星的激波和抗磁腔。给出了海尔-波普彗星在慢速和快速太阳风条件下等离子体环境的详细模拟结果。我们还计算了1997年4月11日观测条件下的合成H2O+、CO+和软x射线图像。
MHD simulation results of the interaction of the expanding atmosphere of comet Hale-Bopp with the magnetized solar wind are presented. At the upstream boundary a supersonic and superalfvénic solar wind enters into the simulation box 25 million km upstream of the nucleus. The solar wind is continuously mass loaded with cometary ions originating from the nucleus. The effects of photoionization, recombination and ion-neutral frictional drag are taken into account in the model. The governing equations are solved on an adaptively refined unstructured Cartesian grid using our MUSCL-type upwind numerical technique, MAUS-MHD (Multiscale Adaptive Upwind Scheme for MHD). The combination of the adaptive refinement with the MUSCL-scheme allows the entire cometary atmosphere to be modeled, while still resolving both the shock and the diamagnetic cavity of the comet.Detailed simulation results for the plasma environment of comet Hale-Bopp for slow and fast solar wind conditions are presented. We also calculate synthetic H2O+, CO+ and soft x-ray images for observing conditions on April 11, 1997.