Molecular gas associated with the IRAS-Vela shell

Citation
J. Rajagopal et G. Srinivasan, Molecular gas associated with the IRAS-Vela shell, J ASTROPHYS, 19(3-4), 1998, pp. 79-96
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Space Sciences
Journal title
JOURNAL OF ASTROPHYSICS AND ASTRONOMY
ISSN journal
0250-6335 → ACNP
Volume
19
Issue
3-4
Year of publication
1998
Pages
79 - 96
Database
ISI
SICI code
0250-6335(199812)19:3-4<79:MGAWTI>2.0.ZU;2-V
Abstract
We present a survey of molecular gas in the J = 1 --> 0 transition of (CO)- C-12 towards the IRAS Vela Shell. The shell, previously identified from IRA S maps, is a ring-like structure seen in the region of the Gum Nebula. We c onfirm the presence of molecular gas associated with some of the infrared p oint sources seen along the shell. We have studied the morphology and kinem atics of the gas and conclude that the shell is expanding at the rate of si milar to 13 km s(-1) from a common center. We go on to include in this stud y 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 molecul ar 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 hea d-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 o f being disrupted and swept outwards through the influence of a central OB association, itself born of the parent cloud.