HST Imaging of 3CR Radio Galaxies: The Dust-Radio Connection

Abstract

We used HST, WFPC-2 observations of 40 3CR radio galaxies that show evidence for the presence of dust in the nuclear regions to investigate the connection between the radio source and the dust. The data cover a redshift range 0 < z < 0.5. A large range of dust morphologies is observed, including disk-like and filamentary structures.

We find that there is a connection between the radio source and the dust. There is a strong tendency for the direction of radio source axes and the dust major axes to be perpendicular, and these position angle differences strongly correlate with the morphologies and the linear sizes of the dust features. The radio source has a preference to be perpendicular to the dust major axis when the dust is settled and localized (linear sizes < 2.5 kpc). There is no such a preference when the dust is distributed in a filamentary fashion throughout the radio galaxy.