Model images of radio halos around supernova remnants
Model images of radio halos around supernova remnants
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超新星遗迹周围射电晕的模型图像
DOI：
10.1086/191914
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
S. Reynolds
中科院分区：
文献类型：
--
作者：
S. Reynolds
我目前的模型计算的配置文件和二维图像的无线电同步辐射的年轻超新星遗迹，集中在可观察到的影响相对论电子扩散上游的冲击波。如果震前电子散射的平均自由程足够长，则可能会在射电辐射的大部分之外产生可观察到的同步加速器晕;它们的缺失会限制来自上方的平均自由程。如果散射如预期的那样主要是由于振幅为detla（B）的阿尔芬波，则预计晕将在激波之外延伸r（sub g）c（delta（B）/B）（exp 2）/v（sub s）级的距离，其中r（sub g）是以观察到的频率发射的电子的回旋半径，B是上游磁场强度，v（sub s）是激波速度，振幅δ（B）是指波长与r（sub g）相当的波，对于典型的超新星遗迹参数为10（exp 13）cm量级。然而，晕的详细几何形状随着关于冲击波中粒子加速的假设而变化。我提出了一个图集的模型配置文件和图像作为震前扩散长度的函数，磁场和视线之间的方位角，以及其他相关参数。
I present model calculations of profiles and two-dimensional images of the radio synchrotron emission of young supernova remnants, concentrating on observable effects of relativistic eletrons diffusing upstream of the shock wave. If the preshock electron scattering mean free path is sufficiently long, observable synchrotron halos outside the bulk of the radio emission can potentially result; their absence can constrain the mean free path from above. If scattering is primarily due, as expected, to Alfven waves with amplitude detla(B), the halo is expected to extend a distance of order r(sub g)c(delta(B)/B)(exp 2)/v(sub s) beyond the shock, where r(sub g) is the gyroradius of the electrons emitting at the observed frequency, B is the upstream magnetic field strength, v(sub s) is the shock velocity, and the amplitude delta(B) refers to wave with wavelength comparable to r(sub g), of order 10(exp 13) cm for typical supernova-remnant parameters. However, the detailed geometry of the halo varies with the assumptions about particle acceleration in the shock wave. I present an atlas of model profiles and images as a function of preshock diffusion length, of aspect angle between the magnetic field and the line of sight, and of other relevant parameters.