Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Departure of high temperature iron lines from the equilibrium state in
  flaring solar plasmas   The aim of this study is to clarify if the assumption of ionization
equilibrium and a Maxwellian electron energy distribution is valid in flaring
solar plasmas. We analyze the 2014 December 20 X1.8 flare, in which the
\ion{Fe}{xxi} 187~\AA, \ion{Fe}{xxii} 253~\AA, \ion{Fe}{xxiii} 263~\AA\ and
\ion{Fe}{xxiv} 255~\AA\ emission lines were simultaneously observed by the EUV
Imaging Spectrometer onboard the Hinode satellite. Intensity ratios among these
high temperature Fe lines are compared and departures from isothermal
conditions and ionization equilibrium examined. Temperatures derived from
intensity ratios involving these four lines show significant discrepancies at
the flare footpoints in the impulsive phase, and at the looptop in the gradual
phase. Among these, the temperature derived from the
\ion{Fe}{xxii}/\ion{Fe}{xxiv} intensity ratio is the lowest, which cannot be
explained if we assume a Maxwellian electron distribution and ionization
equilibrium, even in the case of a multi-thermal structure. This result
suggests that the assumption of ionization equilibrium and/or a Maxwellian
electron energy distribution can be violated in evaporating solar plasma around
10~MK.

9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
23
The categories of this paper are: solv-int