Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A "diamond-ring" star: the unusual morphologic structure of a young
  (multiple?) object   We have observed IRAS06468-0325 obtaining optical and infrared images through
IJHKs and L' filters, K-band low-resolution spectroscopy, together with
millimetre line observations of CO and CS. IRAS06468-0325 has a very unusual
and enigmatic morphology with two components: a bright, close to point-like
source (the diamond) and a sharp-edge ring-like structure (the ring). The
source is not detected in the optical, at wavelengths shorter than the I-band.
The diamond is seen in all the imaging bands observed. The ring-like structure
in IRAS06468-0325 is clearly seen in the I, J, H, and Ks. It is not detected in
the L'-band image. Infrared colours of the diamond are compatible with excess
circumstellar emission and a young stellar nature. A strongly non-gaussian and
moderately bright CO(1-0) and {13}CO(2-1) lines are seen towards
IRAS06468-0325, at v_{LSR} of 30.5 km s{-1} (corresponding to a kinematic
distance of 3 kpc). Very weak C{18}O(2-1) and CS(2-1) lines were detected.
K-band spectra of the diamond and of the ring are similar both in the slope of
the continuum and in the presence of lines supporting the idea that the ring is
reflected light from the diamond. With the current data, a few different
scenarios are possible to explain the morphology of this object. However, the
available data seem to favour that the morphology of IRAS06468-0325 correspond
to a young stellar multiple system in a transient stage where a binary
co-exists with a circumbinary disc, similar to the case of GG Tau. In this
case, the sharpness of the well-defined ring may be due to tidal truncation
from dynamic interactions between components in a binary or multiple stellar
system. IRAS06468-0325 may be an important rare case that illustrates a
short-lived stage of the process of binary or multiple star formation.

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The categories of this paper are: hep-ex
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The categories of this paper are: math-ph
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The categories of this paper are: econ
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The categories of this paper are: chao-dyn
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The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: cond-mat
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The categories of this paper are: patt-sol
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The categories of this paper are: math
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The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: quant-ph