Neutrino emission from an off-axis jet driven by the tidal disruption event AT2019dsg

Recently, a high-energy muon neutrino event was detected in association with a tidal disruption event (TDE) AT2019dsg at the time about 150 days after the peak of the optical/UV luminosity. We propose that such an association could be interpreted as arising from hadronic interactions between relativistic protons accelerated in the jet launched from the TDE and the intense radiation field of TDE inside the optical/UV photosphere, if we are observing the jet at a moderate angle (i.e., approximately 10 ° -3 0 ° ) with respect to the jet axis. Such an off-axis viewing angle leads to a high gas column density in the line of sight, which provides a high opacity for the photoionization and the Bethe-Heitler process and allows the existence of an intrinsic long-term x-ray radiation of comparatively high emissivity. As a result, the cascade emission accompanying the neutrino production, which would otherwise overshoot the flux limits in the x-ray and/or GeV band, is significantly obscured or absorbed. Since the jets of TDEs are supposed to be randomly oriented in the sky, the source density rate of TDE with an off-axis jet is significantly higher than that of TDE with an on-axis jet. Therefore, an off-axis jet is naturally expected in a nearby TDE being discovered, supporting the proposed scenario.