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Full-Text Articles in Physical Sciences and Mathematics
On The Time-Frequency Downward Drifting Of Repeating Fast Radio Bursts, Weiyang Wang, Bing Zhang, Xuelei Chen, Renxin Xu
On The Time-Frequency Downward Drifting Of Repeating Fast Radio Bursts, Weiyang Wang, Bing Zhang, Xuelei Chen, Renxin Xu
Physics & Astronomy Faculty Research
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 …
Coherent Radio Emission From A Twisted Magnetosphere After A Magnetar-Quake, Weiyang Wang, Bing Zhang, Xuelei Chen, Renxin Xu
Coherent Radio Emission From A Twisted Magnetosphere After A Magnetar-Quake, Weiyang Wang, Bing Zhang, Xuelei Chen, Renxin Xu
Physics & Astronomy Faculty Research
Magnetars are a class of highly magnetized, slowly rotating neutron stars, only a small fraction of which exhibit radio emission. We propose that the coherent radio curvature emission is generated by net charge fluctuations from a twist-current-carrying bundle (the j-bundle) in the scenario of magnetar-quake. Two-photon pair production is triggered, which requires a threshold voltage not too much higher than 109 V in the current-carrying bundle, and which can be regarded as the "open field lines" of a magnetar. Continued untwisting of the magnetosphere maintains change fluctuations, and hence coherent radio emission, in the progressively shrinking j-bundle, which lasts for …
Investigation Of The Asteroid - Neutron Star Collision Model For The Repeating Fast Radio Burst, Jeremy L. Smallwood, Rebecca G. Martin, Bing Zhang
Investigation Of The Asteroid - Neutron Star Collision Model For The Repeating Fast Radio Burst, Jeremy L. Smallwood, Rebecca G. Martin, Bing Zhang
Physics & Astronomy Faculty Research
The origin of fast radio bursts (FRBs) is still a mystery. One model proposed to interpret the only known repeating object, FRB 121102, is that the radio emission is generated from asteroids colliding with a highly magnetized neutron star (NS). With N-body simulations, we model a debris disc around a central star with an eccentric orbit intruding NS. As the NS approaches the first periastron passage, most of the comets are scattered away rather than being accreted by the NS. To match the observed FRB rate, the debris belt would have to be at least 3 orders of magnitude more …