Effective radii and color gradients in radio galaxies

Abstract

We present de Vaucouleurs' effective radii in Band R bands for a sample of MRC radio galaxies and a control sample of normal galaxies. We use the ratio of the scale lengths in the two bands as an indicator to show that the radio galaxies tend to have excess of blue color in their inner region much more frequently than the control galaxies. We show that the scale length ratio is a useful indicator of radial color variation even when the conventional color gradient is too noisy to serve the purpose. We also discuss other interesting morphological features of radio galaxies including departures from de Vaucouleurs' law profiles in their central regions.