The nature of radio-quiet QSO's VLA observations of 0026+129, 0205+024 and 1351+640.

Abstract

VLA maps of 'radio-quiet' QSOs are reported. Extended emission is found on linear scales of about 10 kpc, larger than that observed in Seyfert galaxies, but smaller than most radio-loud objects. The spectral properties of some radio-quiet objects are also very similar to those of radio-quiet Seyfert galaxies such as NGC 4151; some radio-quiet QSOs are probably just luminous Seyfert galaxies. There is no sign of either external or self-absorption of a radio-loud core. Thermal gas suppression due to the emission-line material cold mask the appearance of a very compact core. However, unlike their radio-loud counterparts, the radio-quiet QSOs must not eject large numbers of relativistic particles over scales larger than that of the emission-line gas. The ejection trigger may be the primary discriminant between radio-loud and radio-quiet QSOs, and may be luminosity-related.