Radio properties of NLS1s

While NLS1s have been studied intensively at X-ray and optical wavelengths, comparatively little is known about their characteristics in the radio ban d. Therefore, we have carried out an investigation of the radio luminositie s, source sizes, spectral index distribution, and variability of a large, u niformly selected sample of NLS1s. Our results indicate that, in some respe cts, the radio properties of NLS1s differ from those of classical Seyfert g alaxies. Radio observations of NLS1s may thus provide important clues regar ding the nature of their nuclear activity. (C) 2000 Published by Elsevier S cience B.V. All rights reserved.