Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The nature of HH 223 from long-slit spectroscopy   HH 223 is a knotty, wiggling nebular emission of ~30" length found in the
L723 star-forming region. It lies projected onto the largest blueshifted lobe
of the cuadrupolar CO outflow powered by a low-mass YSO system embedded in the
core of L723. We analysed the physical conditions and kinematics along HH 223
with the aim of disentangling whether the emission arises from shock-excited,
supersonic gas characteristic of a stellar jet, or is only tracing the wall
cavity excavated by the CO outflow. We performed long-slit optical spectroscopy
along HH 223, crossing all the bright knots (A to E) and part of the
low-brightness emission nebula (F filament). One spectrum of each knot,
suitable to characterize the nature of its emission, was obtained. The physical
conditions and the radial velocity of the HH 223 emission along the slits were
also sampled at smaller scale (0.6") than the knot sizes. {The spectra of all
the HH 223 knots appear as those of the intermediate/high excitation
Herbig-Haro objects. The emission is supersonic, with blueshifted peak
velocities ranging from -60 to -130 km/s. Reliable variations in the kinematics
and physical conditions at smaller scale that the knot sizes are also found.
The properties of the HH 223 emission derived from the spectroscopy confirm the
HH nature of the object, the supersonic optical outflow most probably also
being powered by the YSOs embedded in the L723 core.

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The categories of this paper are: hep-ph
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The categories of this paper are: adap-org
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The categories of this paper are: physics
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The categories of this paper are: hep-th
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
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The categories of this paper are: quant-ph
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-bio
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The categories of this paper are: comp-gas
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The categories of this paper are: acc-phys
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The categories of this paper are: cs
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The categories of this paper are: dg-ga
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The categories of this paper are: supr-con