Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Plasmoid ejection by Alfv\'en waves and the fast radio bursts from SGR
  1935+2154   Using numerical simulations we show that low-amplitude Alfv\'en waves from a
magnetar quake propagate to the outer magnetosphere and convert to "plasmoids"
(closed magnetic loops) which accelerate from the star, driving blast waves
into the magnetar wind. Quickly after its formation, the plasmoid becomes a
thin relativistic pancake. It pushes out the magnetospheric field lines, and
they gradually reconnect behind the pancake, generating a variable wind far
stronger than the normal spindown wind of the magnetar. Repeating ejections
drive blast waves in the amplified wind. We suggest that these ejections
generate the simultaneous X-ray and radio bursts detected from SGR 1935+2154. A
modest energy budget of the magnetospheric perturbation $\sim 10^{40}$ erg is
sufficient to produce the observed bursts. Our simulation predicts a narrow (a
few ms) X-ray spike from the magnetosphere, arriving almost simultaneously with
the radio burst emitted far outside the magnetosphere. This timing is caused by
the extreme relativistic motion of the ejecta.

10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc