Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Global VLBI Observations of Compact Radio Sources in M82   Observations of the starburst galaxy, M82, have been made with a 20-station
global VLBI array at $\lambda$18cm. Maps are presented of the brightest young
supernova remnants (SNR) in M82 and the wide-field mapping techniques used in
making images over a field of view of $\sim$1 arcminute with 3 milliarcsecond
resolution are discussed. A limit has been placed on the power law deceleration
of the young SNR, 43.31+592 with an index greater than 0.73 $\pm$ 0.11 from
observations with the European VLBI Network. Using the global array we have
resolved compact knots of radio emission in the source which, with future
global observations, will enable better constraints to be placed on the
expansion parameters of this SNR.
  The latest global observations have also provided high resolution images of
the most compact radio source in M82, 41.95+575. We determine an upper limit to
the radial expansion rate along the major axis of 2000 km s$^{-1}$. However,
the new images also show structure resembling that of collimated ejection which
brings into question the previous explanation of the source as being due to the
confinement of a supernova by a high density circumstellar medium.
  It is apparent that we are now able to image the brightest supernova remnants
in M82 with a linear scale which allows direct comparison with galactic SNR
such as Cassiopeia A.

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The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-th
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The categories of this paper are: q-fin
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The categories of this paper are: cmp-lg
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The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: funct-an