Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extraplanar gas in Edge-on Galaxies traced by SOFIA observations of [C
  II]   Bursts of localized star formation in galaxies can levitate material from
their midplanes. Spiral galaxies that are edge-on allow clear distinction of
material that is levitated off the galaxies' midplanes. We used SOFIA to
measure the vertical distribution of [C II] 157.7 micron line emission for two
nearby, edge-on galaxies, NGC 891 and NGC 5907. We find that for the central
region and actively-star-forming regions in the northern portion of NGC 891,
and for NGC 5907, a thin (0.3 kpc) disk is supplemented by a thick disk with an
exponential scale height of about 2 kpc. The [C II] is far more extended than
mid-infrared emission (0.1 kpc, tracing present-day massive star formation) but
not as extended as the H I (100 kpc, tracing low-metallicity
circum/inter-galactic matter). The extraplanar [C II] may arise in walls of
chimneys that connect the disk to the halo.

14
The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
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The categories of this paper are: physics
32
The categories of this paper are: atom-ph
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The categories of this paper are: hep-th
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The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg