Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Molecular gas associated with the IRAS-Vela shell   We present a survey of molecular gas in the J = 1 -> 0 transition of 12CO
towards the IRAS Vela shell. The shell, previously identified from IRAS maps,
is a ring-like structure seen in the region of the Gum Nebula. We confirm the
presence of molecular gas associated with some of the infrared point sources
seen along the Shell. We have studied the morphology and kinematics of the gas
and conclude that the shell is expanding at the rate of ~ 13 km/s from a common
center. We go on to include in this study the Southern Dark Clouds seen in the
region. The distribution and motion of these objects firmly identify them as
being part of the shell of molecular gas. Estimates of the mass of gas involved
in this expansion reveal that the shell is a massive object comparable to a
GMC. From the expansion and various other signatures like the presence of
bright-rimmed clouds with head-tail morphology, clumpy distribution of the gas
etc., we conjecture that the molecular gas we have detected is the remnant of a
GMC in the process of being disrupted and swept outwards through the influence
of a central OB association, itself born of the parent cloud.

9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ