Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: X-ray Star Clusters in the Carina Complex   The distribution of young stars found in the Chandra Carina Complex Project
(CCCP) is examined for clustering structure. X-ray surveys are advantageous for
identifying young stellar populations compared to optical and infrared surveys
in suffering less contamination from nebular emission and Galactic field stars.
The analysis is based on smoothed maps of a spatially complete subsample of
about 3000 brighter X-ray sources classified as Carina members, and about
10,000 stars from the full CCCP sample. The principal known clusters are
recovered, and some additional smaller groups are identified. No rich embedded
clusters are present, although a number of sparse groups are found. The CCCP
reveals considerable complexity in clustering properties. The Trumpler 14 and
15 clusters have rich stellar populations in unimodal, centrally concentrated
structures several parsecs across. Non-spherical internal structure is seen,
and large-scale low surface density distributions surround these rich clusters.
Trumpler 16, in contrast, is comprised of several smaller clusters within a
circular boundary. Collinder 228 is a third type of cluster which extends over
tens of parsecs with many sparse compact groups likely arising from triggered
star formation processes. A widely dispersed, but highly populous, distribution
of X-ray stars across the about 50 pc CCCP mosaic supports a model of past
generations of star formation in the region. Collinder 234, a group of massive
stars without an associated cluster of pre-main sequence stars, may be part of
this dispersed population.

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The categories of this paper are: mtrl-th
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The categories of this paper are: physics
8
The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: hep-th
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The categories of this paper are: atom-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg