Landing page for project ES107

We discovered a unique "changing-look" AGN candidate, which has changed from a LINER to typical AGN, but remains at high accretion state over only several years. With GMRT, VLA,VLBA and EVN observations, we identified highly variable radio emission and dramatic spectral evolution, which can be best explained by the evolution of multiple synchrotron self-absorbed spectral components. Such a radio evolution could represent a novel phenomenon of violent jet ejections during the transition between a radiatively inefficient and efficient accretion state, unseen previously in AGNs. We have been awarded new e-MERLIN and VLA multi-frequency observations to further monitor the spectral evolution down to a cadence of ~1 month, which can determine key physical parameters of jet ejections, such as kinetic energy, expansion velocity and launching intervals. We hereby request coordinated EVN observations at C-band, with immediate aim to follow and quantify the evolution of the jet on mas-scales. Coupled with radio spectral variations, the EVN data can help to establish the link of jet evolution to the changes in accretion rate as traced by the on-going X-ray and UV monitoring campaigns with the Swift observatory.

This data is part of the archive of VLBI data maintained by JIVE on behalf of the EVN, a network of radio telescopes located primarily in Europe and Asia, with additional antennas in South Africa. The EVN archive itself has the DOI https://doi.org/10.17616/R3Z197