Document Type
Article
Publication Date
5-3-2019
Publication Title
The Astrophysical Journal Letters
Publisher
American Astronomical Society
Volume
876
Issue
1
First page number:
1
Last page number:
5
Abstract
The newly discovered second repeating fast radio burst (FRB) source, FRB 180814.J0422+73, was reported to exhibit a time–frequency downward drifting pattern, which is also seen in the first repeater FRB 121102. We propose a generic geometrical model to account for the observed downward drifting of sub-pulse frequency, within the framework of coherent curvature radiation by bunches of electron–positron pairs in the magnetosphere of a neutron star (NS). A sudden trigger event excites these coherent bunches of charged particles, which stream outward along open field lines. As the field lines sweep across the line of sight, the bunches seen later travel farther into the less-curved part of the magnetic field lines, thus emitting at lower frequencies. We use this model to explain the time–frequency downward drifting in two FRB generation scenarios, the transient pulsar-like sparking from the inner gap region of a slowly rotating NS, and the externally triggered magnetosphere reconfiguration known as the "cosmic comb."
Keywords
Plusars: general; Radiation mechanisms: non-thermal; Radio continuum: general; Stars: neutron
Disciplines
Astrophysics and Astronomy
File Format
File Size
469 KB
Language
English
Repository Citation
Wang, W.,
Zhang, B.,
Chen, X.,
Xu, R.
(2019).
On the Time-Frequency Downward Drifting of Repeating Fast Radio Bursts.
The Astrophysical Journal Letters, 876(1),
1-5.
American Astronomical Society.
http://dx.doi.org/10.3847/2041-8213/ab1aab