Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: FACT -- Multi-wavelength analysis of more than 30 flares of Mrk 421   Mrk 421 is a high-synchrotron-peaked blazar featuring bright and persistent
GeV and TeV emission. We use multi-wavelength light curves of Mrk 421 spanning
5.5 years with FACT (TeV) and Fermi LAT (GeV) in the gamma rays, Swift BAT,
Swift XRT and MAXI in the X-rays, together with optical and radio data and
investigate the physical processes driving the emission and variability.
Observations by FACT are continuous and not triggered, so the source was found
in a wide range of flux states and more than 30 flares were identified from
X-rays to TeV. The light curves in TeV and X-rays feature very similar flares
with rise and decay times of a few days and zero lag, characteristic for
electron processes. At least two parameters per flare, the amplitude and the
cut-off energy, are required to explain the observed variability. In addition,
the GeV light curve leads and is strongly correlated with the optical and radio
light curves as expected from SSC emitting shock propagating in a conical jet.

16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
29
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: atom-ph
1
The categories of this paper are: cs
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The categories of this paper are: econ
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: patt-sol
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex