New SiO maser sources : red-supergiants in the vicinity of molecular clouds.
Abstract
A search for SiO maser emission has been made toward H2O/infrared objects which are found in the vicinity of star-forming regions, but which are not coincident with radio continuum sources. SiO emission was detected in GL 2103, GL 2139, GL 2999, and GL 1074. The first three sources show SiO emission with a single velocity component of large width, 10 to 15 km/s. Their OH masers have large circular polarization and wide velocity spread (30 to 40 km/s). These maser spectra together with the infrared suggest that these objects are red supergiants. They have radial velocities similar to those of the molecular cloud complexes in their vicinities. The luminosities of GL 2103 and GL 2139, based on their kinematic distances, are three million and four million solar luminosities, respectively, which are comparable to that of VY CMa. No SiO masers similr to the Orion SiO source were found.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 1984
- Bibcode:
- 1984A&A...138..194U
- Keywords:
-
- Infrared Spectra;
- Interstellar Masers;
- Molecular Clouds;
- Red Giant Stars;
- Silicon Oxides;
- Supergiant Stars;
- Hydroxyl Emission;
- Molecular Spectra;
- Water;
- Astrophysics