Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: ORFEUS II echelle spectra: deuterium and molecular hydrogen in the ISM
  towards BD +39 3226   In ORFEUS II spectra of the sdO star BD +39 3226 interstellar hydrogen and
deuterium is detected. From Ly alpha profile fitting and a curve of growth
analysis of the Lyman series of H I and D I we derive the column densities
N(H)=1.20(+0.28/-0.22)*10^20 cm^(-2) and N(D)=1.45(+0.50/-0.38)*10^(15)
cm^(-2). From the analysis of metal absorption lines in ORFEUS and IUE spectra
we obtain column densities for 11 elements. In addition, we examine absorption
lines of H_2 for rotational excitation states up to J=7. We find an H_2
ortho-to-para ratio of 2.5, the fractional abundance of molecular hydrogen has
a low value of log f=-4.08 for a total amount of N(H_2)=4.8(+2.0/-1.6)*10^15
cm^(-2). The column densities of the excitation states reveal a moderate
Boltzmann excitation temperature of 130 K and an equivalent excitation
temperature for the excited upper states due to UV pumping of <1800 K.

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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: cond-mat
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The categories of this paper are: ao-sci
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The categories of this paper are: stat
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The categories of this paper are: atom-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: supr-con
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The categories of this paper are: solv-int
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The categories of this paper are: cs
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: nucl-ex