Landing page for project EV028

Luminous outbursts, as tracers of Tidal Disruption Events (TDEs) are observed at different wavelengths when a star approaches a supermassive black hole. Carrying out high-resolution radio observations are essential to follow-up the evolution of TDEs, even years after the event, and potentially catch the formation of jets or delayed, non-relativistic outflows. AT2019aalc, is one of the three TDE candidates found to be coincident with a high-energy neutrino event so far and notably produces the highest neutrino fluence. We have observed the source June 2023 at 1.6GHz with the EVN+e-MERLIN. The source experienced a significant optical rebrightening at this time. The preliminary results of our multi-wavelength campaign during the new flare suggest the presence of highly asymmetric outflows or a (choked) jet which were launched probably between the two optical flares. We propose 23GHz follow-up observations in order to be able to resolve the point-like source we detected in L-band and find outflow signatures. Delayed outflows are common features of TDEs and help us to classify the source and to understand the two flares. Outflows/choked jets are key elements of several models proposed to explain the neutrino emission.

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