Radio emission and the optical isophotal twist of radio-loud ellipticals

Abstract

Using the surface photometric analysis data for a well defined sample of 79 nearby radio galaxies (z≤0.12 ), it is shown that the level of radio emission associated with an elliptical galaxy during the radio-loud phase is related to the presence of large amounts of isophotal twist in its optical image. In particular, radio galaxies with P₄₀₈ >3 ×10²⁵ W Hz^-1 appear to show a preference to be associated with elliptical hosts exhibiting an isophotal twist in excess of ~20° .