Radio continuum morphology of southern Seyfert galaxies

Citation
R. Morganti et al., Radio continuum morphology of southern Seyfert galaxies, ASTR AST SS, 137(3), 1999, pp. 457-471
Citations number
50
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES
ISSN journal
03650138 → ACNP
Volume
137
Issue
3
Year of publication
1999
Pages
457 - 471
Database
ISI
SICI code
0365-0138(199906)137:3<457:RCMOSS>2.0.ZU;2-C
Abstract
We present radio observations for 29 southern Seyfert galaxies selected fro m a volume limited sample with cz < 3600 km s(-1), and declination delta < 0 degrees. Objects with declination -30 degrees < delta < 0 degrees were ob served with the Very Large Array (VLA) at 6 cm (4.9 GHz) and objects with d elta < -30 degrees were observed with the Australia Telescope Compact Array (ATCA) at 3.5 cm (8.6 GHz). Both the VLA and the ATCA observations have a resolution of similar to 1". These new observations cover more than 50% of the southern sample with all but two of the 29 objects detected above our l imit of 0.15 mJy. Combining these data with data available from the literat ure gives almost 85% coverage of the southern sample and further expands th e radio observations of a distance limited sample by 22%. Collecting additional sources from the literature, consisting of known Seyf erts with cz < 4600 km s(-1), we find that 38% of the sources are unresolve d at arcsecond resolution, and 34% have linear radio structure. Our results expand upon and are consistent with earlier studies. We confirm a correlat ion between the size of the radio structure and the radio luminosity. A com parison between Seyfert types 1 and 2 finds that type 2s tend to have a lar ger 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.