FRB 200428: An Impact between an Asteroid and a Magnetar
Abstract
A fast radio burst (FRB) was recently detected to be associated with a hard X-ray burst from the Galactic magnetar SGR 1935+2154. Scenarios involving magnetars for FRBs are hence highly favored. In this work, we suggest that the impact between an asteroid and a magnetar could explain such a detection. According to our calculations, an asteroid of mass 1020 g will be disrupted at a distance of 7 × 109 cm when approaching the magnetar. The accreted material will flow along the magnetic field lines from the Alfvén radius ∼107 cm. After falling onto the magnetar's surface, an instant accretion column will be formed, producing a Comptonized X-ray burst and an FRB in the magnetosphere. We show that all the observational features of FRB 200428 could be interpreted self-consistently in this scenario. We predict quasi-periodic oscillations in this specific X-ray burst, which can serve as an independent observational test.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2020
- DOI:
- 10.3847/2041-8213/aba83c
- arXiv:
- arXiv:2006.04601
- Bibcode:
- 2020ApJ...898L..55G
- Keywords:
-
- Minor planets;
- Pulsars;
- Radio pulsars;
- Magnetars;
- Soft gamma-ray repeaters;
- Astronomical radiation sources;
- Burst astrophysics;
- Non-thermal radiation sources;
- Neutron stars;
- Radio bursts;
- 1065;
- 1306;
- 1353;
- 992;
- 1471;
- 89;
- 187;
- 1119;
- 1108;
- 1339;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 5 pages, 1 figure. References updated, accepted by ApJL