Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Effect of Active Galactic Nuclei on the Mid-Infrared Aromatic
  Features   We present Spitzer measurements of the aromatic (also known as PAH) features
for 35 Seyfert galaxies from the revised Shapley-Ames sample and find that the
relative strengths of the features differ significantly from those observed in
star-forming galaxies. Specifically, the features at 6.2, 7.7, and 8.6 micron
are suppressed relative to the 11.3 micron feature in Seyferts. Furthermore, we
find an anti-correlation between the L(7.7 micron)/L(11.3 micron) ratio and the
strength of the rotational H2 (molecular hydrogen) emission, which traces
shocked gas. This suggests that shocks suppress the short-wavelength features
by modifying the structure of the aromatic molecules or destroying the smallest
grains. Most Seyfert nuclei fall on the relationship between aromatic emission
and [Ne II] emission for star-forming galaxies, indicating that aromatic-based
estimates of the star-formation rate in AGN host galaxies are generally
reasonable. For the outliers from this relationship, which have small L(7.7
micron)/L(11.3 micron) ratios and strong H2 emission, the 11.3 micron feature
still provides a valid measure of the star-formation rate.

14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
1
The categories of this paper are: cs