Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: IRTF/TEXES Observations of the HII Regions H1 and H2 in the Galactic
  Centre   We present new [Ne II] (12.8 micron) IRTF/TEXES observations of the Galactic
Center HII regions H1 and H2, which are at a projected distance of ~11 pc from
the center of the Galaxy. The new observations allow to map the radial velocity
distributions of ionized gas. The high spectroscopic resolution (~4 km/s) helps
us to disentangle different velocity components and enables us to resolve
previous ambiguity regarding the nature of these sources. The spatial
distributions of the intensity and radial velocity of the [Ne II] line are
mapped. In H1, the intensity distributions of the Paschen-\alpha (1.87 micron)
and [Ne II] lines are significantly different, which suggests a strong
variation of extinction across the HII region of A_K~0.56. The radial velocity
distributions across these HII regions are consistent with the predictions of a
bow-shock model for H1 and the pressure-driven model for H2. Furthermore, we
find a concentration of bright stars in H2. These stars have similar H-K_s
colors and can be explained as part of a 2 Myr old stellar cluster. H2 also
falls on the orbit of the molecular clouds, suggested to be around Sgr A*. Our
new results confirm what we had previously suggested: the O supergiant P114 in
H1 is a runaway star, moving towards us through the -30-0 {km/s} molecular
cloud, whereas the O If star P35 in H2 formed in-situ, and may mark the
position of a so-far unknown small star cluster formed within the central 30 pc
of the Galaxy.

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The categories of this paper are: q-bio
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The categories of this paper are: dg-ga
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The categories of this paper are: cond-mat
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin
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The categories of this paper are: eess
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The categories of this paper are: chao-dyn
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The categories of this paper are: supr-con
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The categories of this paper are: hep-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: mtrl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: econ