Jet Properties and Evolution in Small and Intermediate Scale Objects

Abstract

Kinematic and spectral studies are improving our knowledge of the age distribution in compact radio sources, providing evidence that small sources are generally very young. The properties of jets in objects spanning the size range from a few tens of parsecs to some kiloparsecs become then of particular interest. Because of our selection criteria and of the small scales involved, the properties of jets in the population of Compact Symmetric Objects (CSO) are not well known yet. Polarization properties seem to indicate a strong influence by the interaction with the dense surrounding medium, and some objects show evidence of relativistic bulk motion. More evolved jets are present in the class of Low Power Compact (LPC) sources and a number of cases are discussed here. Since it is becoming increasingly clear that not all these sources will survive to evolve into large scale radio galaxies, the question of the final evolution of the CSO and LPC population is also discussed, with examples of candidate dying sources.