Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Detection of two bright radio bursts from magnetar SGR 1935+2154   Fast radio bursts (FRBs) are millisecond-duration, bright radio signals
(fluence $\mathrm{0.1 - 100\,Jy\,ms}$) emitted from extragalactic sources of
unknown physical origin. The recent CHIME/FRB and STARE2 detection of an
extremely bright (fluence $\sim$MJy$\,$ms) radio burst from the Galactic
magnetar SGR~1935$+$2154 supports the hypothesis that (at least some) FRBs are
emitted by magnetars at cosmological distances. In follow-up observations
totalling 522.7$\,$hrs on source, we detect two bright radio bursts with
fluences of $112\pm22\mathrm{\,Jy\,ms}$ and $24\pm5\mathrm{\,Jy\,ms}$,
respectively. Both bursts appear affected by interstellar scattering and we
measure significant linear and circular polarisation for the fainter burst. The
bursts are separated in time by $\sim$1.4$\,$s, suggesting a non-Poissonian,
clustered emission process -- similar to what has been seen in some repeating
FRBs. Together with the burst reported by CHIME/FRB and STARE2, as well as a
much fainter burst seen by FAST (fluence 60$\mathrm{\,mJy\,ms}$), our
observations demonstrate that SGR 1935+2154 can produce bursts with apparent
energies spanning roughly seven orders of magnitude, and that the burst rate is
comparable across this range. This raises the question of whether these four
bursts arise from similar physical processes, and whether the FRB population
distribution extends to very low energies ($\sim10^{30}\,$erg, isotropic
equivalent).

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The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
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The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
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The categories of this paper are: eess
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
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The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol