Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-Resolution Molecular Line Observations of the Environment of the
  Class 0 Source B1-IRS   In this work we present VLA observations of the NH3, CCS, and H2O maser
emission at 1 cm from the star forming region B1-IRS (IRAS 03301+3057) with ~
5" (=1750 AU) of angular resolution. CCS emission is distributed in three
clumps around the central source. These clumps exhibit a velocity gradient from
red- to blueshifted velocities toward B1-IRS, probably due to an interaction
with the outflow from an embedded protostar. The outflow and its powering
source are traced by a reflection nebula and an associated infrared point
source detected in a 2MASS K-band image. We find that this infrared point
source is associated with water maser emission distributed in an elongated
structure (~ 450 AU size) along the major axis of the reflection nebula and
tracing the base of the outflow of the region. Ammonia emission is extended and
spatially anticorrelated with CCS. This is the first time that this kind of
anticorrelation is observed in a star forming region with such a high angular
resolution, and illustrates the importance of time-dependent chemistry on small
spatial scales. The relatively large abundance of CCS with respect to ammonia,
compared with other star forming regions, suggests an extreme youth for the
B1-IRS object (<10E+5 yr). We suggest the possibility that CCS abundance is
enhanced via shock-induced chemistry.

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The categories of this paper are: math
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The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: physics
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The categories of this paper are: q-fin
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The categories of this paper are: gr-qc
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-th
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The categories of this paper are: chem-ph