The DRAGN is breathing fire

Image may be NSFW.
Clik here to view.© Vikram Singh

Radio-loud galaxies are a subset of AGN that show enormous regions of radio emission outside the visible extent of the host galaxy. In the nearby universe, these double-lobed radio emissions have almost invariably been associated with elliptical galaxies. It has long been theorized (and supported by observations) that elliptical galaxies are formed by the merger of smaller galaxies and that such mergers provide the mechanism for the infall of gas into the accreting regions of the nucleus. It has also been proposed that such mergers are what result in the launching of kiloparsec-scale radio-loud jets from the central AGN by spinning up the supermassive black hole.

0313-192 was the first confirmed double-lobed radio source hosted by a late-type galaxy and is the archetype for the Spiral DRAGN (Double Radio sources associated with Active Galactic Nuclei) phenomenon. The image above shows the preliminary results from the reduction of S-band (13cm) data obtained from the VLBA (Very Large Baseline Array, USA). It confirms beyond doubt that the radio source associated with 0313-192 is not a chance alignment. The angle of the milli-arcsecond scale jet seen matches (within error) with previously obtained images from the VLA and VLBA (3.6cm, X-band). A comparison with the X-band image yields a core spectral index of α = -0.46 confirming that the core is optically thick (very dense) and that synchrotron self-absorption is taking place at these frequencies. The next step for the team is to reduce L-band (21 cm) data from the VLBA to study the HI absorption in the galaxy.