Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-velocity-resolution observations of OH main line lasers in the M82
  starburst   Using the VLA, a series of high velocity resolution observations have been
made of the M82 starburst at 1.6 GHz. These observations follow up on previous
studies of the main line OH maser emission in the central kiloparsec of this
starburst region, but with far greater velocity resolution, showing significant
velocity structure in some of the maser spots for the first time. A total of
thirteen masers were detected, including all but one of the previously known
sources. While some of these masers are still unresolved in velocity, these new
results clearly show velocity structure in spectra from several of the maser
regions. Position-velocity plots show good agreement with the distribution of
H{\sc i} including interesting velocity structure on the blueward feature in
the west of the starburst which traces the velocity distribution seen in the
ionised gas.

31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph