High resolution radio observations of G 49.5-0.4 (W51).
Abstract
The H II region G49.5-0.4 (W51), has been mapped at frequencies of 5 and 15 GHz with respective angular resolutions of 2 x 8 and 0.65 x 2.6 arcsec. The brighter of the two main components is optically-thin and resolved by the beam at the higher frequency; its radio brightness distribution is consistent with that of the corresponding 20-micron infrared source. The second component comprises a compact core with ridges of emission extending a distance of some 1.5 arcsec (2 pc). An unresolved, optically-thick continuum source has been detected close to the main W51 H2O maser source. The data are consistent with the second component being adjacent to a dense molecular cloud, on the edge of which more OB stars are forming.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 1978
- DOI:
- 10.1093/mnras/183.3.435
- Bibcode:
- 1978MNRAS.183..435S
- Keywords:
-
- Astronomical Maps;
- Microwave Emission;
- Radio Astronomy;
- B Stars;
- H Ii Regions;
- Hydrogen Atoms;
- Hydrogen Ions;
- Masers;
- O Stars;
- Astronomy;
- H II Regions:Contour Maps;
- H II Regions:Infrared Sources;
- H II Regions:Molecular Clouds;
- H II Regions:Radio Radiation