Astroplasmas Seminar

Fridays at 12:30pm, Dome Room, Peyton Hall

Next seminar

Friday, September 24th 2021, 12.30pm

Electromagnetic fireworks: Fast radio bursts from rapid reconnection in the compressed magnetar wind

Jens F. Mahlmann (Princeton University)

Abstract: It was recently proposed that extragalactic fast radio bursts can be produced during magnetic reconnection in a compressed current sheet of the magnetar wind, triggered by the strong fast magnetosonic pulse produced by a magnetar flare. The current sheet is fragmented into a self-similar chain of magnetic islands and the coherent radiation is produced by time-dependent plasma currents at their interfaces during coalescence. We investigate this scenario using 2D radiative relativistic particle-in-cell simulations. We compute the efficiency of the coherent emission and obtain scalings for its peak frequency. Consistent with expectations, a fraction of the incident magnetic flux, scaling with the reconnection rate, is reconnected and converted into fireworks of high-frequency fast waves with an efficiency factor f~0.002. In analogy to previous analytical estimates, we find that fast magnetosonic pulses can trigger relatively narrow-band GHz emission with radio luminosities sufficient to explain extragalactic fast radio bursts. The mechanism also provides a natural explanation for the nanosecond sub-structure recently detected in FRB 20200120E.

Scheduled seminars (September to December 2021)

24 Sept: Jens Mahlmann (Princeton University)

01 Oct: Bart Ripperda (Center for Computational Astrophysics and Princeton University)

08 Oct: David Hosking (Oxford University)

15 Oct: Ben Prather (University of Illinois)

22 Oct: Aaron Tram (Columbia University) and Luciano Combi (Instituto Argentino de RadioastronomĂ­a)

29 Oct: Tamar Faran (The Hebrew University of Jerusalem) and Itai Linial (The Hebrew University of Jerusalem)

05 Nov: Lorenzo Perrone (Cambridge University)

19 Nov: Fabio Bacchini (University of Colorado)

03 Dec: Elias Most (Institute of Advanced Studies and Princeton University)

10 Dec: Elizabeth Tolman (Institute of Advanced Studies)