The electron temperatures of H II regions determined from radio recombination line observations at 22 GHz.
Abstract
Radial velocities, line widths, and LTE electron temperatures obtained from H66-alpha and H83-beta radio recombination-line observations and radio continuum measurements are presented for 15 galactic H II regions observed at 22.4 GHz with a resolution of about 43 arcsec. The H83-beta/H66-alpha line intensity ratio is measured for five sources and shown to be consistent with LTE. An average LTE electron temperature of 7900 K is determined for the surveyed sources; it is concluded that there are no large electron-temperature gradients in these sources and that the effects of source geometry are small at 22.4 GHz. The data are compared with previous observations of the H109-alpha and H137-beta radio recombination line. The H66-alpha results are found to be consistent with a proposed gradient in the electron temperatures of H II regions with distance from the galactic center.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 1979
- Bibcode:
- 1979A&A....71..205W
- Keywords:
-
- Electron Energy;
- H Ii Regions;
- Radial Velocity;
- Radiative Recombination;
- Spectral Line Width;
- Angular Resolution;
- Flux Density;
- High Frequencies;
- Line Spectra;
- Noise Temperature;
- Normal Density Functions;
- Recombination Coefficient;
- Stark Effect;
- Temperature Gradients;
- Thermodynamic Equilibrium;
- Astrophysics;
- Electron Temperatures:H II Regions;
- H II Regions:Radio Radiation;
- H II Regions:Recombination Lines