3D Magnetothermal Simulations of Tangled Crustal Magnetic Field in Central Compact Objects
3D Magnetothermal Simulations of Tangled Crustal Magnetic Field in Central Compact Objects
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中心致密天体中纠缠地壳磁场的 3D 磁热模拟
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
T. Wood
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文献类型：
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作者：
A. Igoshev;K. Gourgouliatos;Rainer Hollerbach;T. Wood
中心致密天体（CCO）是年轻的中子星，其辐射热光度L X在1032-1034 erg s−1之间。Gourgouliatos，Hollerbach和Igoshev最近提出，CCO的特殊发射特性可以用在原中子星星阶段随机发电机中形成的纠缠磁场结构来解释。在这种情况下，磁场由多个小尺度分量组成，全局偶极场的贡献可以忽略不计。我们研究了中子星中纠缠地壳磁场的三维磁热演化。我们发现，所有的配置产生复杂的表面热图案，包括多个小的热区位于彼此之间的显着分离。初始磁能为（2.5-10）× 1047 erg的组态的热区温度达到10.2keV，与我们在无冷却条件下模拟的10.1keV的体温度进行比较。在对CCO的观测中也看到了温度的两倍。热点在光变曲线中产生周期性调制，典型幅度为≤9%-11%。因此，纠缠的磁场位形可以解释一些CCO的热发射特性。
Central compact objects (CCOs) are young neutron stars emitting thermal X-rays with bolometric luminosities L X in the range of 1032–1034 erg s−1. Gourgouliatos, Hollerbach, and Igoshev recently suggested that peculiar emission properties of CCOs can be explained by tangled magnetic field configurations formed in a stochastic dynamo during the proto–neutron star stage. In this case the magnetic field consists of multiple small-scale components with negligible contribution of global dipolar field. We study numerically three-dimensional magnetothermal evolution of tangled crustal magnetic fields in neutron stars. We find that all configurations produce complicated surface thermal patterns that consist of multiple small hot regions located at significant separations from each other. The configurations with initial magnetic energy of (2.5–10) × 1047 erg have temperatures of hot regions that reach ≈ 0.2 keV, to be compared with the bulk temperature of ≈ 0.1 keV in our simulations with no cooling. A factor of two in temperature is also seen in observations of CCOs. The hot spots produce periodic modulations in light curve with typical amplitudes of ≤9%–11%. Therefore, the tangled magnetic field configuration can explain thermal emission properties of some CCOs.