Broadband radio observations of low-frequency variable sources
Abstract
Data on the spectral variations of 135 low-frequency variables observed at seven frequencies between 325 MHz and 15 GHz, over a period of two years are analyzed. Evidence of variability at frequencies below 1000 MHz were found in eight sources and probably two additional objects may be variable. With one exception, all were flat-spectrum sources, principally quasars. For the great majority of the sources, only upper limits to variability at frequencies around 400 MHz were observed, and the data show that the events are often discernible to quite high frequencies (15-31 GHz), suggesting an 'intermediate frequency gap' in which the event is not seen.
- Publication:
-
The Astronomical Journal
- Pub Date:
- May 1981
- DOI:
- 10.1086/112938
- Bibcode:
- 1981AJ.....86..730S
- Keywords:
-
- Broadband;
- Extragalactic Radio Sources;
- Low Frequency Bands;
- Radio Astronomy;
- Variability;
- Quasars;
- Tables (Data);
- Astrophysics