Radio continuum morphology of southern Seyfert galaxies.
MORGANTI R., TSVETANOV Z.I., GALLIMORE J. and ALLEN M.G.
Abstract (from CDS):
We present radio observations for 29 southern Seyfert galaxies selected from a volume limited sample with cz<3600km/s, and declination δ<0°. Objects with declination -30°<δ<0° were observed with the Very Large Array (VLA) at 6cm (4.9GHz) and objects with δ←30° were observed with the Australia Telescope Compact Array (ATCA) at 3.5cm (8.6GHz). Both the VLA and the ATCA observations have a resolution of ∼1". These new observations cover more than 50% of the southern sample with all but two of the 29 objects detected above our limit of 0.15mJy. Combining these data with data available from the literature gives almost 85% coverage of the southern sample and further expands the radio observations of a distance limited sample by 22%. Collecting additional sources from the literature, consisting of known Seyferts with cz<4600km/s, we find that 38% of the sources are unresolved at arcsecond resolution, and 34% have linear radio structure. Our results expand upon and are consistent with earlier studies. We confirm a correlation between the size of the radio structure and the radio luminosity. A comparison between Seyfert types 1 and 2 finds that type 2s tend to have a larger linear size. There is no statistically significant difference in radio power between types 1 and 2, although all the most powerful objects appear to be Seyfert 2's. No significant difference has been found in the spectral indices.
radio continuum: galaxies - galaxies: Seyfert