Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Model of the W3(OH) environment based on data for both maser and
  'quasi-thermal' methanol lines   In studies of the environment of massive young stellar objects, recent
progress in both observations and theory allows a unified treatment of data for
maser and 'quasi-thermal' lines. Interferometric maser images provide
information on the distribution and kinematics of masing gas on small spatial
scales. Observations of multiple masing transitions provide constraints on the
physical parameters.
  Interferometric data on 'quasi-thermal' molecular lines permits an
investigation of the overall distribution and kinematics of the molecular gas
in the vicinity of young stellar objects, including those which are deeply
embedded. Using multiple transitions of different molecules, one can obtain
good constraints on the physical and chemical parameters.
  Combining these data enables the construction of unified models, which take
into account spatial scales differing by orders of magnitude.
  Here we present such a combined analysis of the environment around the
ultracompact HII region in W3(OH). This includes the structure of the methanol
masing region, physical structure of the near vicinity of W3(OH), detection of
new masers in the large-scale shock front and embedded sources in the vicinity
of the TW young stellar object.

15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci