Radio line and continuum observations of ten small Sharpless H II regions.
Abstract
Ten optically visible H II regions have been observed in the H 109-alpha, H 137-beta, and H I lines. In general the H 109-alpha radial velocities agree with those measured in H-alpha. For sources in the Perseus arm, H I velocities tend to be lower than the velocities of the nebula. The velocities of the ionized gas are generally in good agreement with the CO radial velocities. This correlation suggests an association of the ionized gas with the molecular cloud. Finally, distance estimates are given for the ten nebulae, and their physical parameters are derived from measured continuum and line parameters.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 1977
- Bibcode:
- 1977A&A....60..293K
- Keywords:
-
- Absorption Spectra;
- H Alpha Line;
- H Ii Regions;
- Nebulae;
- Radial Velocity;
- Astrometry;
- Distance;
- Hydrogen Ions;
- Ionized Gases;
- Molecular Absorption;
- Radiative Recombination;
- Radio Observation;
- Astrophysics