Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Maxi observations of long X-ray bursts   We report nine long X-ray bursts from neutron stars, detected with Monitor of
All-sky X-ray Image (MAXI). Some of these bursts lasted for hours, and hence
are qualified as superbursts, which are prolonged thermonuclear flashes on
neutron stars and are relatively rare events. MAXI observes roughly 85% of the
whole sky every 92 minutes in the 2-20 keV energy band, and has detected nine
bursts with a long e-folding decay time, ranging from 0.27 to 5.2 hours, since
its launch in 2009 August until 2015 August. The majority of the nine events
were found to originate from transient X-ray sources. The persistent
luminosities of the sources, when these prolonged bursts were observed, were
lower than 1% of the Eddington luminosity for five of them and lower than 20%
for the rest. This trend is contrastive to the 18 superbursts observed before
MAXI, all but two of which originated from bright persistent sources. The
distribution of the total emitted energy, i.e., the product of e-folding time
and luminosity, of these bursts clusters around $10^{41}$-$10^{42}$ erg,
whereas either of the e-folding time and luminosity ranges for an order of
magnitude. Among the nine events, two were from 4U 1850-086 during the phases
of relatively low persistent-flux, whereas it usually exhibits standard short
X-ray bursts during outbursts.

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The categories of this paper are: q-alg
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The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: physics
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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: math-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: q-bio
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The categories of this paper are: econ
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The categories of this paper are: patt-sol
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-lat