• Media type: E-Article
  • Title: Fast Radio Burst Breakouts from Magnetar Burst Fireballs
  • Contributor: Ioka, Kunihito
  • Published: American Astronomical Society, 2020
  • Published in: The Astrophysical Journal Letters, 904 (2020) 2, Seite L15
  • Language: Not determined
  • DOI: 10.3847/2041-8213/abc6a3
  • ISSN: 2041-8205; 2041-8213
  • Origination:
  • Footnote:
  • Description: Abstract The recent discovery of a Mega-Jansky radio burst occurring simultaneously with short X-ray bursts from the Galactic magnetar (strongly magnetized neutron star (NS)) SGR 1935+2154 is a smoking gun for the hypothesis that some cosmological fast radio bursts (FRBs) arise from magnetar bursts. We argue that the X-ray bursts with high temperature T ≳ 30 keV entail an electron–positron (e ±) outflow from a trapped–expanding fireball, polluting the NS magnetosphere before the FRB emission. The e ± outflow is opaque to induced Compton scatterings of FRB photons, and is strongly Compton-dragged by the X-ray bursts. Nevertheless, the FRB photons can break out of the e ± outflow with radiation forces if the FRB emission radius is larger than a few tens of NS radii. A FRB is choked if the FRB is weaker or the X-ray bursts are stronger, possibly explaining why there are no FRBs with giant flares and no detectable X-ray bursts with weak FRBs. We also speculate that the e ± outflow may be inevitable for FRBs, solving the problem of why the FRBs occur only with high-T X-ray bursts. The breakout physics is important for constraining the emission mechanism and electromagnetic counterparts to future FRBs.
  • Access State: Open Access