Frequency drifts in FRBs due to radius-to-frequency mapping in magnetospheres of neutron stars
arXiv:1908.07313
Abstract
We interpret recent observations of high-to-low frequency drifting features in the spectra of the repeating FRBs as evidence of sharply changing plasma properties in the emission region, presumably the neutron stars magnetospheres. The drifts are then FRBs' analogues of radius-to-frequency mapping in pulsars and Solar type-III radio burst (but not in a sense of a particular emission mechanism). The drifts rates of MHz ms at frequencies GHz translate to physical size of few cm, matching the hypothesis of the FRB origin in the magnetospheres of neutron stars. We suggest that reconnection events result in generation of upward propagating plasma beams that produce radio emission with frequency related to the decreasing local magnetic field and plasma density.
arXiv admin note: substantial text overlap with arXiv:1901.03260