The nature of radio-quiet quasars.
Abstract
We report 13 mm continuum observations of all "radio-quiet" quasars with good IRAS observations. The 1.3 mm emission is so weak compared to the 100 micron emission as to lead us to suggest that dust emission on kpc scale, powered by the active nucleus, explains the FIR spectrum. A self-absorbed synchrotron source model cannot be fitted to the data for the majority of the sources in our sample. The radio emission appears to be dominated by weak radio galaxy emission in most cases, and only rarely by normal spiral galaxy disk emission. In a two color diagram of radio to far-infrared spectral index α_IRX_ versus far-infrared to X-ray spectral index α_IRX_ starburst galaxies, the various kinds of Seyfert galaxies and radio galaxies are clearly separated. The "radio-quiet" quasars of our sample, for which radio and X-ray data are available, demonstrate that they span the same properties as Seyfert 2 to Seyfert 1 galaxies. It follows that sensitive radio observations of radio-weak quasars require both spectral and high spatial resolution before one can infer any contribution of relativistically boosted emission.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 1989
- Bibcode:
- 1989A&A...219...87C
- Keywords:
-
- Astronomical Spectroscopy;
- Quasars;
- Radio Galaxies;
- Starburst Galaxies;
- Active Galactic Nuclei;
- Cosmic Dust;
- Far Infrared Radiation;
- Infrared Astronomy Satellite;
- Radio Emission;
- X Ray Spectra;
- Astrophysics