Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The impact of new ionizing fluxes on ISO observations of HII regions and
  starbursts   Extensive grids of photoionization models have been calculated for single
star HII regions and evolving starbursts. We illustrate the predictions for IR
fine structure lines which are used to analyse the stellar content, and derive
properties such as the age and IMF. The impact of recent ionizing fluxes on the
IR lines are shown. First comparisons of our starburst models with
IR-diagnostics and the ISO observations of Genzel et al. (1998) are also
presented.

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The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
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The categories of this paper are: dg-ga
16
The categories of this paper are: stat
3
The categories of this paper are: physics