TY - JOUR
T1 - Electromagnetic Fireworks
T2 - Fast Radio Bursts from Rapid Reconnection in the Compressed Magnetar Wind
AU - Mahlmann, J. F.
AU - Philippov, A. A.
AU - Levinson, A.
AU - Spitkovsky, A.
AU - Hakobyan, H.
N1 - Funding Information:
We thank Bart Ripperda for testing our setup in their MHD code BHAC , and Miguel A. Aloy for their insight into the corresponding MHD discontinuities. We appreciate the help of Daniel Grošelj, who assisted in optimizing the dispersive properties of our field solver, and Joonas Nättilä who shared their insight into stabilizing dispersion errors of highly nonlinear waves in PIC. We also thank Lorenzo Sironi and Chris Thompson for insightful discussions related to this model. We welcome the improvements to the discussion of our model suggested by a thorough referee. This research is supported in part by NASA grant 80NSSC18K1099 and NSF grant PHY-1804048. A.A.P. and J.F.M. acknowledge support from the National Science Foundation under grant No. AST-1909458. A.L. acknowledges support from the Israel Science Foundation grant 1114/17. This research is part of the Frontera (Stanzione et al. ) computing project at the Texas Advanced Computing Center (LRAC-AST21006). Frontera is made possible by National Science Foundation award OAC-1818253. The presented numerical simulations were further enabled by the MareNostrum supercomputer (Red Española de Supercomputación, AECT-2021-1-0006), and the Stellar cluster (Princeton Research Computing). Research at the Flatiron Institute is supported by the Simons Foundation.
Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/6/1
Y1 - 2022/6/1
N2 - One scenario for the generation of fast radio bursts (FRBs) is magnetic reconnection in a current sheet of the magnetar wind. Compressed by a strong magnetic pulse induced by a magnetar flare, the current sheet fragments into a self-similar chain of magnetic islands. Time-dependent plasma currents at their interfaces produce coherent radiation during their hierarchical coalescence. We investigate this scenario using 2D radiative relativistic particle-in-cell simulations to compute the efficiency of the coherent emission and to obtain frequency scalings. Consistent with expectations, a fraction of the reconnected magnetic field energy, f ∼0.002, is converted to packets of high-frequency fast magnetosonic waves, which can escape from the magnetar wind as radio emission. In agreement with analytical estimates, we find that magnetic pulses of 1047 erg s-1 can trigger relatively narrowband GHz emission with luminosities of approximately 1042 erg s-1, sufficient to explain bright extragalactic FRBs. The mechanism provides a natural explanation for a downward frequency drift of burst signals, as well as the 1/4100 ns substructure recently detected in FRB 20200120E .
AB - One scenario for the generation of fast radio bursts (FRBs) is magnetic reconnection in a current sheet of the magnetar wind. Compressed by a strong magnetic pulse induced by a magnetar flare, the current sheet fragments into a self-similar chain of magnetic islands. Time-dependent plasma currents at their interfaces produce coherent radiation during their hierarchical coalescence. We investigate this scenario using 2D radiative relativistic particle-in-cell simulations to compute the efficiency of the coherent emission and to obtain frequency scalings. Consistent with expectations, a fraction of the reconnected magnetic field energy, f ∼0.002, is converted to packets of high-frequency fast magnetosonic waves, which can escape from the magnetar wind as radio emission. In agreement with analytical estimates, we find that magnetic pulses of 1047 erg s-1 can trigger relatively narrowband GHz emission with luminosities of approximately 1042 erg s-1, sufficient to explain bright extragalactic FRBs. The mechanism provides a natural explanation for a downward frequency drift of burst signals, as well as the 1/4100 ns substructure recently detected in FRB 20200120E .
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U2 - 10.3847/2041-8213/ac7156
DO - 10.3847/2041-8213/ac7156
M3 - Article
AN - SCOPUS:85132948333
SN - 2041-8205
VL - 932
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L20
ER -