Dynamical Models of Tailed Radio Sources in Clusters of Galaxies

TLDR: In this article, two models for the formation of tailed radio sources like 3C 129 are developed, one of which is a modification of current models of normal symmetric double radio sources, with the effects of the motion of the parent galaxy and of the thermal pressure of the intracluster gas included.

Abstract: Two medels for the formation of tailed'' radio sources like 3C 129 are developed. Both models assume that the tails are the result of the rapid motion of an active galaxy through the relatively dense gas in a cluster of galaxies. The first model is a modification of current models of normal symmetrical double radio sources, with the effects of the motion of the parent galaxy and of the thermal pressure of the intracluster gas included. The second model assumes that the galaxy has a long, permanently attached, magnetospheric tail, similar to the geomagnetic tail, generated by the action of the intracluster gas flow on the intrinsic magnetic field of the galaxy. This tail is illuminated at intervals by outbursts of high energy electrons from the galaxy. An attempt is made to fit both models to 3C 129 to see if they give a good explanation of the observed characteristics of this source, and to determine the physical conditions in the intracluster gas. While both models give good fits to the shape of the tail, the magnetospheric model gives a better fit to the observed spectral indices, more » as well as relbes ia the interpretation of the polarization solving some difficulties in the interpretation of the polarization of the radio emission of 3C 129. The relation of the models to normal symmetric double radio sources, and to intermediate cases like 3C 465 is discussed. The derived values of the intracluster density and temperature are considered. (auth) « less