Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: EUV Spectra of Solar Flares from the EUV Spectroheliograph SPIRIT aboard
  CORONAS-F satellite   We present detailed EUV spectra of 4 large solar flares: M5.6, X1.3, X3.4,
and X17 classes in the spectral ranges 176-207 \AA\ and 280-330 \AA. These
spectra were obtained {by the slitless} spectroheliograph SPIRIT aboard the
CORONAS-F satellite. To our knowledge these are the first detailed EUV spectra
of large flares obtained with spectral resolution of $\sim 0.1$ \AA. We
performed a comprehensive analysis of the obtained spectra and provide
identification of the observed spectral lines. The identification was performed
based {on the calculation} of synthetic spectra (CHIANTI database was used),
with simultaneous {calculations of DEM} and density of the emitting plasma.
More than 50 intense lines are present in the spectra that correspond to a
temperature range of $T=0.5-16$ MK; most of the lines belong to Fe, Ni, Ca, Mg,
Si ions. In all the considered flares intense hot lines from Ca XVII, Ca XVIII,
Fe XX, Fe XXII, and Fe XXIV are observed. The calculated DEMs have a peak at $T
\sim 10$ MK. The densities were determined using Fe XI - Fe XIII lines and
averaged $6.5 \times 10^9$ cm$^{-3}$. We also discuss the identification,
accuracy and major discrepancies of the spectral line intensity prediction.

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The categories of this paper are: math
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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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: dg-ga
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The categories of this paper are: plasm-ph
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The categories of this paper are: nlin
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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: cs
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int