Abstract of the proposal for the experiment ES091A


When a star passes too close to a supermassive black hole, it can be tidally disrupted, producing a luminous flare of electromagnetic radiation peaking at optical/UV. Until recently, transient mid-IR emission from a few candidates of tidal disruption events (TDEs) has been discovered. This emission is best understood as originating from dust heated by nuclear flares, offering a new window to probe the circumnuclear dust and gas, and even jet production. Using data from the WISE surveys, we have compiled a new sample of such TDE-like candidates. With JVLA observations at 5GHz, we revealed a high radio detection rate (~75%) above 60uJy that is completely unexpected. Our VLBA follow-ups of two brightest sources confirm the transient nature of radio emission but result in distinct radio slopes. Here we request further EVN observations at L- and C-band for another two objects with a slightly lower radio flux, from which transient coronal lines have been observed. Timely EVN observations will be used to probe the radio structure at milliarcsecond scale, resolving jetlike/outflow components if present. Accurate measurements of radio spectral slope will help confirm any variability and understand the radio radiation mechanism of MIR-burst sources.