Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Metal enrichment of the neutral gas of blue compact dwarf galaxies: the
  compelling case of Pox 36   We present the analysis of the interstellar spectrum of Pox 36 with the Far
Ultraviolet Spectroscopic Explorer (FUSE). Pox 36 was selected because of the
relatively low foreground gas content that makes it possible to detect
absorption-lines weak enough that unseen components should not be saturated.
Interstellar lines of HI, NI, OI, SiII, PII, ArI, and FeII are detected. Column
densities are derived directly from the observed line profiles except for HI,
whose lines are contaminated by stellar absorption. We used the TLUSTY models
to remove the stellar continuum and isolate the interstellar component. The
best fit indicates that the dominant stellar population is B0. The fit of the
interstellar HI line gives a column density of 10^{20.3\pm0.4} cm-2. Chemical
abundances were then computed from the column densities using the dominant
ionization stage in the neutral gas. Our abundances are compared to those
measured from emission-line spectra in the optical. Our results suggest that
the neutral gas of Pox 36 is metal-deficient by a factor ~7 as compared to the
ionized gas, and they agree with a metallicity of ~1/35 Z$_\odot$. Conclusions:
The abundance discontinuity between the neutral and ionized phases implies that
most of the metals released by consecutive star-formation episodes mixes with
the HI gas. The volume extent of the enrichment is so large that the
metallicity of the neutral gas increases only slightly. The star-forming
regions could be enriched only by a small fraction (~1%), but it would greatly
enhance its metallicity. Our results are compared to those of other BCDs. We
confirm the overall underabundance of metals in their neutral gas, with perhaps
only the lowest metallicity BCDs showing no discontinuity.

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The categories of this paper are: hep-lat
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The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
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The categories of this paper are: q-fin
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The categories of this paper are: dg-ga
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-th