Very long baseline interferometric observations of OH masers associated with infrared stars.
Abstract
Interferometric observations of 12 OH/IR sources at 1612 MHz were made on a baseline having a minimum fringe spacing of 0.045 arcsec. IRC + 10011, IRC + 50137, OH 1735-32, OH 1821-12, OH 1837-05, OH 1854+02, R Aql, and IRC -20540 produced no interference fringes, so the individual features in these sources were presumed to be larger than 0.06 arcsec. Fringes on the sources VY CMa, VX Sgr, W43 A, and NMI Cyg were seen, and maps of their principal features produced. All the features in these sources had fringe visibilities of less than 0.3, except for one feature in VY CMa that was unresolved. The brightness temperatures of the features were typically 10 billion K. Attempts were made to understand the geometry of the distribution of the maser emission in terms of an expanding spherical shell model.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1977
- DOI:
- 10.1086/154914
- Bibcode:
- 1977ApJ...211..160M
- Keywords:
-
- Hydroxyl Emission;
- Infrared Stars;
- Interferometry;
- Interstellar Masers;
- Stellar Envelopes;
- Astronomical Maps;
- Brightness Temperature;
- Infrared Astronomy;
- Maser Outputs;
- Molecular Spectra;
- Power Spectra;
- Stellar Models;
- Astrophysics