arXiv subjects
Publications and source records attributed to Magdalena Kunert.
We report early results of an observational campaign targeted on a sample of compact steep spectrum sources selected from the FIRST survey which are significantly weaker than those investigated before. The selection criteria and procedure are given in detail. We present here an assortment of MERLIN and VLBI observations and make some general comments based on the morphologies of the sources presented.
According to the currently accepted paradigm compact steep spectrum (CSS) sources are precursors of larger/older objects and gigahertz peaked spectrum (GPS) sources may be earlier stages of CSS sources. In this paper we confront this paradigm with the outcome of recent observations of CSS sources that are significantly weaker than those known before. In particular we claim that not all CSS sources must end up as large scale objects; if the activity phase of an AGN's central engine is shorter than the lifetime of a large scale radio source (up to ~10^8 years) the radio source associated with such an AGN decays earlier, e.g. at the CSS stage. We point out that a theory of thermal-viscous instabilities in the accretion disks of AGN may explain many features of radio sources at all stages of their evolution.