Radius-to-frequency Mapping and FRB Frequency Drifts
Radius-to-frequency Mapping and FRB Frequency Drifts
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DOI：
10.3847/1538-4357/ab55de
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发表时间：
2019-09
期刊：
影响因子：
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通讯作者：
M. Lyutikov
中科院分区：
文献类型：
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作者：
M. Lyutikov
本文建立了中子星磁层半径-频率映射模型，并将其应用于快射电暴（FRB）中观测到的频率漂移。我们假设一个发射补丁传播沿着的偶极磁场线，产生相干发射的频率，方向和偏振定义的本地磁场。观测到的频率随时间的演化取决于时间收缩的相对论效应和磁力线的曲率。该模型一般产生漂移率的线性缩放，在数值上和参数上都与FBR中观察到的速率相匹配;也可能有更复杂的行为。快速旋转的磁层产生更高的漂移率相似的观察参数比缓慢旋转的。在中继站的情况下，同一个源可能会显示不同的漂移模式，这取决于观测阶段。我们预计偏振位置角的旋转通过一个突发，虽然由较小的数额比无线电脉冲星。所有这些发现与FBR的性质相比都是有利的，加强了它们在中子星磁层中的可能位置。
We build a model of radius-to-frequency mapping in magnetospheres of neutron stars and apply it to frequency drifts observed in fast radio bursts (FRBs). We assume that an emission patch propagates along the dipolar magnetic field lines, producing coherent emission with frequency, direction, and polarization defined by the local magnetic field. The observed temporal evolution of the frequency depends on the relativistic effects of time contraction and the curvature of the magnetic field lines. The model generically produces linear scaling of the drift rate, , matching both numerically and parametrically the rates observed in FBRs; a more complicated behavior of is also possible. Fast rotating magnetospheres produce higher drifts rates for similar viewing parameters than the slowly rotating ones. In the case of repeaters, the same source may show variable drift patterns depending on the observing phase. We expect rotational of polarization position angle through a burst, though by smaller amount than in radio pulsars. All of these findings compare favorably with properties of FBRs, strengthening their possible loci in the magnetospheres of neutron stars.