Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Can the Kappa-distributed electron energies account for the intensity
  ratios of O II lines in photoionized gaseous nebulae?   A vexing puzzle in the study of planetary nebulae and \ion{H}{2} regions is
that the plasma diagnostic results based on collisionally excited lines
systematically differ from those based on recombination lines. A fairly
speculative interpretation is the presence of nonthermal electrons with the
so-called $\kappa$ energy distributions, yet there is little observational
evidence to verify or disprove this hypothesis. In this paper, we examine the
influence of $\kappa$-distributed electrons on the emissivities of \ion{O}{2}
recombination lines using an approximate method, where the rate coefficients
for a $\kappa$ distribution are computed by summing Maxwellian-Boltzmann rate
coefficients with appropriate weights. The results show that if invoking
$\kappa$-distributed electrons, the temperatures derived from the [\ion{O}{3}]
$(\lambda4959+\lambda5007)/\lambda4363$ ratios could coincide with those
estimated from the \ion{O}{2} $\lambda4649/\lambda4089$ ratios. However, the
estimated temperatures and $\kappa$ values are not in agreement with those
obtained through comparing the [\ion{O}{3}]
$(\lambda4959+\lambda5007)/\lambda4363$ ratios and the hydrogen recombination
spectra, suggesting that the electron energy is unlikely to follow the
$\kappa$-distributions over a global scale of the nebular regions.
Nevertheless, based on this observation alone, we cannot definitely rule out
the presence of $\kappa$-distributed electrons in some microstructures within
nebulae.

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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: nlin
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The categories of this paper are: funct-an
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: cond-mat
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The categories of this paper are: cs
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The categories of this paper are: math-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
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The categories of this paper are: econ
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The categories of this paper are: physics