Radio emission from outflow–cloud interaction and its constraint on tidal disruption event outflow

ABSTRACT Tidal disruption event (TDE) can launch an ultrafast outflow. If the black hole is surrounded by large amounts of clouds, outflow–cloud interaction will generate bow shocks, accelerate electrons, and produce radio emission. Here, we investigate between a non-relativistic outflow clouds in active galaxies, which manifested as outflow–BLR (broad-line region) interaction, be extended to outflow–torus interaction. This process considerable emission, may account for flares appearing few months later after TDE outbursts. Benefitting from efficient energy conversion shocks strong magnetic field, play non-negligible, or even dominating role generating cloudy circumnuclear environment if CNM density no more than 100 times Sgr A*-like one. In this case, evolution spectra used directly constrain properties outflows.