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 the interaction between a non-relativistic outflow and clouds in active galaxies, which is manifested as outflow-BLR (broad line region) interaction, and can be extended to outflow-torus interaction. This process can generate considerable radio emission, which may account for the radio flares appearing a few months later after TDE outbursts. Benefitting from efficient energy conversion from outflow to shocks and the strong magnetic field, outflow-cloud interaction may play a non-negligible, or even dominating role in generating radio flares in a cloudy circumnuclear environment if the CNM density is no more than 100 times the Sgr A*-like one. In this case, the evolution of radio spectra can be used to directly constrain the properties of outflows.
@article{arxiv.2108.11296,
title = {Radio Emission from Outflow-Cloud Interaction and Its Constraint on TDE Outflow},
author = {Guobin Mou and Tinggui Wang and Wei Wang and Jingjing Yang},
journal= {arXiv preprint arXiv:2108.11296},
year = {2022}
}
Comments
8 pages, 4 figures. Accepted for publication in MNRAS