Radio continuum observations of blue compact dwarf galaxies.
Abstract
A sample of 52 blue compact dwarf and low surface brightness galaxies has been observed at a wavelength of 6.3 cm using the Effelsberg 100-m radio telescope. The flux densities which have been derived for the sample are compared with global properties in other spectral domains. On average, blue compact dwarf galaxies exhibit about 10 times higher radio-to-optical luminosity than normal spirals. There is evidence that the relation between the radio and the optical luminosity of blue compact dwarf galaxies is different from that found for normal spirals. The average radio continuum spectra of blue compact dwarf galaxies appears to be significantly flatter, suggesting a low fraction of synchrotron radiation. Since these blue galaxies show clear evidence for violent star formation taking place at present, nonthermal emission is expected to be present due to supernova events. It is suggested that weak magnetic fields in blue compact dwarf galaxies are the reason for this weak synchrotron emission.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- December 1984
- Bibcode:
- 1984A&A...141..241K
- Keywords:
-
- Compact Galaxies;
- Continuous Radiation;
- Dwarf Galaxies;
- Radio Emission;
- Radio Spectra;
- Interstellar Magnetic Fields;
- Luminosity;
- Magnitude;
- Nonthermal Radiation;
- Radiant Flux Density;
- Spiral Galaxies;
- Stellar Evolution;
- Supernovae;
- Synchrotron Radiation;
- Astrophysics