Hotspot advance speed - hotspot size/core-hotspot distance relation

Abstract

We examined the evolution of extragalactic radio sources using the observed corehotspot distance and hotspot size. Analysis indicates a fairly strong positive correlation in the ratio of core-hotspot distance to hotspot size between that of the approaching arm and the receding arm with a correlation coefficient of r ~ 0.7. Simple kinematic consideration enabled us to obtain an expression to constrain the advance speed of hotspots. In general, the average projected hotspot advance speed estimated for our sample ranges from 0.13 ≤ 〈β〉 ≤ 0.40.

Keywords: Galaxies – General; Galaxies – Active; Methods – Analytical; Methods Data Analysis