COOLING RATES FOR RELATIVISTIC ELECTRONS UNDERGOING COMPTON SCATTERING IN STRONG MAGNETIC FIELDS
COOLING RATES FOR RELATIVISTIC ELECTRONS UNDERGOING COMPTON SCATTERING IN STRONG MAGNETIC FIELDS
复制标题
强磁场中发生康普顿散射的相对论电子的冷却速率
DOI：
10.1088/0004-637x/733/1/61
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
P. Gonthier
中科院分区：
文献类型：
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作者：
M. Baring;Z. Wadiasingh;P. Gonthier
对于高场脉冲星和磁星中硬X射线和伽马射线发射的磁层内模型，共振康普顿上散射被认为是产生连续辐射的最有效过程。这在一定程度上是因为从恒星表面到内部磁层中假定的辐射耗散区域附近有一个热的软光子浴。此外，由于散射过程在回旋频率处变得共振，有效截面比经典汤姆逊值高出两个数量级以上，从而提高了连续谱产生的效率和相对论电子的冷却。本文给出了这种高磁化脉冲星非热辐射的共振康普顿模型所需的电子冷却速率的计算。计算的速率将以前对磁汤姆逊冷却的计算扩展到相对论量子效应的领域，采样在44.13Tg的量子临界磁场附近和之上。这是第一次阐述电子的完全相对论量子磁康普顿冷却速率，它使用了强磁场中康普顿散射的传统Johnson&Lippmann截面和新的Sokolov&Ternov(ST)公式。这种ST形式对于处理与自旋相关的效应是形式上正确的，这些效应在回旋共振中是重要的，以前在康普顿散射冷却的背景下还没有被解决过。正如预期的那样，当反冲和Klein-Nishina减少变得重要时，QED效应被观察到大大降低了低于熟悉的磁汤姆森结果的外推率。
For inner magnetospheric models of hard X-ray and gamma-ray emission in high-field pulsars and magnetars, resonant Compton upscattering is anticipated to be the most efficient process for generating continuum radiation. This is in part due to the proximity of a hot soft photon bath from the stellar surface to putative radiation dissipation regions in the inner magnetosphere. Moreover, because the scattering process becomes resonant at the cyclotron frequency, the effective cross section exceeds the classical Thomson value by over two orders of magnitude, thereby enhancing the efficiency of continuum production and the cooling of relativistic electrons. This paper presents computations of the electron cooling rates for this process, which are needed for resonant Compton models of non-thermal radiation from such highly magnetized pulsars. The computed rates extend previous calculations of magnetic Thomson cooling to the domain of relativistic quantum effects, sampled near and above the quantum critical magnetic field of 44.13 TG. This is the first exposition of fully relativistic, quantum magnetic Compton cooling rates for electrons, and it employs both the traditional Johnson & Lippmann cross section and a newer Sokolov & Ternov (ST) formulation of Compton scattering in strong magnetic fields. Such ST formalism is formally correct for treating spin-dependent effects that are important in the cyclotron resonance and has not been addressed before in the context of cooling by Compton scattering. The QED effects are observed to profoundly lower the rates below extrapolations of the familiar magnetic Thomson results, as expected, when recoil and Klein–Nishina reductions become important.