The disc-dominated host galaxy of FR-I radio source B2 0722+30 |
| |
| Authors: | B H C Emonts C N Tadhunter R Morganti T A Oosterloo J Holt E Brogt G van Moorsel |
| |
| Institution: | CSIRO Australia Telescope National Facility, PO Box 76, Epping, NSW 1710, Australia;Department of Astronomy, Columbia University, Mail Code 5246, 550 West 120th Street, New York, NY 10027, USA;Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH;Netherlands Foundation for Research in Astronomy, Postbus 2, 7990 AA Dwingeloo, the Netherlands;Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, the Netherlands;Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, the Netherlands;The University of Arizona, Steward Observatory, 933 North Cherry Avenue, Tucson, AZ 85721, USA;National Radio Astronomy Observatory, Socorro, NM 87801, USA |
| |
| Abstract: | We present new observational results that conclude that the nearby radio galaxy B2 0722+30 is one of the very few known disc galaxies in the low-redshift Universe that host a classical double-lobed radio source. In this paper, we use H i observations, deep optical imaging, stellar population synthesis modelling and emission-line diagnostics to study the host galaxy, classify the active galactic nucleus (AGN) and investigate environmental properties under which a radio-loud AGN can occur in this system. Typical for spiral galaxies, B2 0722+30 has a regularly rotating gaseous disc throughout which star formation occurs. Dust heating by the ongoing star formation is likely responsible for the high infrared luminosity of the system. The optical emission-line properties of the central region identify a Low Ionization Nuclear Emission-line Region (LINER)-type nucleus with a relatively low O iii ] luminosity, in particular when compared with the total power of the Fanaroff & Riley type-I radio source that is present in this system. This classifies B2 0722+30 as a classical radio galaxy rather than a typical Seyfert galaxy. The environment of B2 0722+30 is extremely H i -rich, with several nearby interacting galaxies. We argue that a gas-rich interaction involving B2 0722+30 is a likely cause for the triggering of the radio AGN and/or the fact that the radio source managed to escape the optical boundaries of the host galaxy. |
| |
| Keywords: | ISM: kinematics and dynamics galaxies: active galaxies: individual: B2 0722+30 galaxies: interactions galaxies: jets galaxies: stellar content |
|
|
