Two-component off-axis jet model for radio flares of tidal disruption events

TL;DR

This paper proposes a two-component off-axis jet model to explain late-time radio rebrightening in tidal disruption events, attributing it to different jet components viewed off-axis, aligning with observed event rates.

Contribution

It introduces a novel two-component jet model for TDE radio flares, explaining late-time rebrightening and matching observed event rate densities.

Findings

Late-time rebrightening explained by off-axis narrow jet component.

Early radio emission attributed to off-axis wide jet component.

Inferred jetted TDE rate density consistent with observations.

Abstract

Recently, radio emission from tidal disruption events (TDEs) has been observed from months to years after the optical discovery. Some of the TDEs including ASASSN-14ae, ASASSN-15oi, AT 2018hyz, and AT 2019dsg are accompanied by the late-time rebrightening phase characterized by a rapid increase in the radio flux. We show that it can be explained by the off-axis two-component jet model, in which the late-time rebrightening arises from the off-axis view of a decelerating narrower jet with an initial Lorentz factor of ~10 and a jet opening angle of ~0.1 rad, while the early-time radio emission is attributed to the off-axis view of a wider jet component. We also argue that the rate density of jetted TDEs inferred from these events is consistent with the observations.