Geodetic VLBI observations of the gamma-bright blazar PKS 0528 + 134

Abstract

With a time sampling of up to one observation per month, the analysis of geodetic VLBI data can reveal a detailed picture of the kinematics in numerous compact radio sources. The database comprises simultaneous observations obtained at two frequencies (8.4 and 2.3 GHz) which have been collected over a period of about 15 years. For our analysis of short-time structural variability in the jets of AGN we selected several sources, mainly on the basis of their flux density variability in the radio and, in case of correlated outbursts and intra-day variability, also in the optical regime. These sources are generally found to be active in the γ-ray regime as well. This fact enables us to study possible correlations between the structural properties seen at radio wavelengths and the flux-density behaviour in the γ-ray regime. The results for the γ-active quasar PKS 0528 + 134 are presented.