Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: X-ray quasi-periodic eruptions from the galactic nucleus of RX
  J1301.9+2747   Following the recent discovery of X-ray quasi-periodic eruptions (QPEs)
coming from the nucleus of the galaxy GSN 069, here we report on the detection
of QPEs in the active galaxy named RX J1301.9+2747. QPEs are rapid and
recurrent increases of the X-ray count-rate by more than one order of magnitude
with respect to a stable quiescent level. During a XMM-Newton observation
lasting 48 ks that was performed on 30 and 31 May 2019, three strong QPEs
lasting about half an hour each were detected in the light curves of RX
J1301.9+2747. The first two QPEs are separated by a longer recurrence time
(about 20 ks) compared to the second and third (about 13 ks). This pattern is
consistent with the alternating long-short recurrence times of the GSN 069
QPEs, although the difference between the consecutive recurrence times is
significantly smaller in GSN 069. Longer X-ray observations will better clarify
the temporal pattern of the QPEs in RX J1301.9+2747 and will allow a detailed
comparison with GSN 069 to be performed. The X-ray spectral properties of QPEs
in the two sources are remarkably similar, with QPEs representing fast
transitions from a relatively cold and likely disk-dominated state to a state
that is characterized by a warmer emission similar to the so-called soft X-ray
excess, a component that is almost ubiquitously seen in the X-ray spectra of
unobscured, radiatively efficient active galaxies. Previous X-ray observations
of RX J1301.9+2747 in 2000 and 2009 strongly suggest that QPEs have been
present for at least the past 18.5 years. The detection of QPEs from a second
galactic nucleus after GSN 069 rules out contamination by a Galactic source in
both cases, such that QPEs ought to be considered a novel extragalactic
phenomenon associated with accreting supermassive black holes.

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The categories of this paper are: math-ph
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The categories of this paper are: cs
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The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-lat
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The categories of this paper are: ao-sci
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The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
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The categories of this paper are: patt-sol
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: physics