FURTHER-STUDIES ON THE CHAMPAGNE PHASE OF GM-24 (IRAS-17136-3617)

DOI: 
10.1086/172661
Publication date: 
20/05/1993
Main author: 
GOMEZ, JF
IAA authors: 
Authors: 
GOMEZ, JF; TORRELLES, JM; TAPIA, M; GOMEZ, Y; RODRIGUEZ, LF; ROTH, M; HO, PTP
Journal: 
ASTROPHYSICAL JOURNAL
Publication type: 
Article
Volume: 
409
Pages: 
269-274
Number: 
Abstract: 
We observed with the VLA the H II region associated with the cometary nebula GM 24 at the 3.6 and 6 cm continuum, the H92alpha recombination line, and the water maser line. These observations suggest the presence of a ''champagne'' flow of ionized gas. We detected two extended radio continuum sources emitting optically thin free-free radiation. The stronger one [S(nu)(total) congruent-to 4 Jy] is associated with GM 24, while the weaker one [S(nu)(total) congruent-to 0.1 Jy], located approximately 1'5 south of GM 24, is related to an optical nebula in the region. The maximum of radio continuum emission coincides with the source IRAS 17136-3617, which is the core of an infrared star cluster. The spectral line data show two velocity components toward GM 24 separated by approximately 10 km s-1. The velocity of the stronger and more compact component is close to the molecular cloud velocity, while its peak of line intensity coincides with the core of the star cluster. The largest H92alpha line widths (DELTAV congruent-to 46 km s-1) are also observed toward this position. The second velocity component (the weaker and extended one) is redshifted by approximately 10 km s-1 with respect to the velocity of the ambient molecular cloud. We suggest as a possible scenario that this velocity component constitutes emission from the ionized gas which is breaking out of the cloud and expanding away from us. A water maser source, with four velocity compoments, is located approximately 15'' southwest of the peak of the radio continuum emission.
Database: 
WOK
Keywords: 
H-II REGIONS; ISM, INDIVIDUAL (GM-24); RADIO CONTINUUM, INTERSTELLAR