Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A sudden period of high activity from repeating Fast Radio Burst
  20201124A   The repeating FRB 20201124A was first discovered by CHIME/FRB in November of
2020, after which it was seen to repeat a few times over several months. It
entered a period of high activity in April of 2021, at which time several
observatories recorded tens to hundreds more bursts from the source. These
follow-up observations enabled precise localization and host galaxy
identification. In this paper, we report on the CHIME/FRB-detected bursts from
FRB 20201124A, including their best-fit morphologies, fluences, and arrival
times. The large exposure time of the CHIME/FRB telescope to the location of
this source allows us to constrain its rates of activity. We analyze the
repetition rates over different spans of time, constraining the rate prior to
discovery to $< 3.4$ day$^{-1}$ (at 3$\sigma$), and demonstrate significant
change in the event rate following initial detection. Lastly, we perform a
maximum-likelihood estimation of a power-law luminosity function, finding a
best-fit index $\alpha = -4.6 \pm 1.3 \pm 0.6$, with a break at a fluence
threshold of $F_{\rm min} \sim 16.6$~Jy~ms, consistent with the fluence
completeness limit of the observations. This index is consistent within
uncertainties with those of other repeating FRBs for which it has been
determined.

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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ph
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The categories of this paper are: math-ph
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The categories of this paper are: q-alg
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The categories of this paper are: physics
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The categories of this paper are: q-fin
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The categories of this paper are: ao-sci
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex
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The categories of this paper are: funct-an
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The categories of this paper are: adap-org
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The categories of this paper are: hep-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg