Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Abundances and Isotope Ratios in the Magellanic Clouds: The Star Forming
  Environment of N113   With the goal of deriving the physical and chemical conditions of star
forming regions in the Large Magellanic Cloud (LMC), a spectral line survey of
the prominent star forming region N113 is presented. The observations cover
parts of the frequency range from 85 GHz to 357 GHz and include 63 molecular
transitions from a total of 16 species, among them spectra of rare
isotopologues. Maps of selected molecular lines as well as the 1.2 mm continuum
distribution are also presented. Molecular abundances in the core of the
complex are found to be consistent with a photon dominated region (PDR) that is
nitrogen deficient, with the potential exception of N2H+. Densities range from
5x10^3 cm-3 for CO to almost 10^6 for CS and HCN, indicating that only the
densest regions provide sufficient shielding even for some of the most common
species. An ortho- to para-H_2CO ratio of ~3 hints at H_2CO formation in a warm
(>=40 K) environment. Isotope ratios are 12C/13C ~ 49+-5, 16O/18O ~ 2000+-250,
18O/17O ~ 1.7+-0.2 and 32S/34S ~ 15. Agreement with data from other star
forming clouds shows that the gas is well mixed in the LMC . The isotope ratios
do not only differ from those seen in the Galaxy. They also do not form a
continuation of the trends observed with decreasing metallicity from the inner
to the outer Galaxy. This implies that the outer Galaxy, is not providing a
transition zone between the inner Galaxy and the metal poor environment of the
Magellanic Clouds. A part of this discrepancy is likely caused by differences
in the age of the stellar populations in the outer Galaxy and the LMC.

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The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
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The categories of this paper are: q-fin
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
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The categories of this paper are: cmp-lg
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The categories of this paper are: eess
7
The categories of this paper are: hep-th