Could TDE outflows produce the PeV neutrino events?

TL;DR

This paper explores whether outflows from tidal disruption events can produce PeV neutrinos through shock interactions with clouds, explaining observed neutrino events like IceCube-191001A.

Contribution

It introduces a model where TDE outflow-cloud interactions generate PeV neutrinos, providing a possible explanation for delayed neutrino detections associated with TDEs.

Findings

Protons can be accelerated up to 60 PeV in the outflow shocks.

The model predicts a neutrino event number of approximately 4×10^{-3} for certain parameters.

Neutrino production depends on uncertain model parameters, involving challenging values to match observations.

Abstract

A tidal disruption event (TDE), AT2019dsg, was observed to be associated with a PeV neutrino event, IceCube-191001A, lagging the optical outburst by a half year. It is known that TDEs may generate ultrafast outflows. If the TDE occurs in a cloudy environment, the outflow-cloud interactions may form shock waves which generate accelerated protons and hence delayed neutrinos from hadronic interactions in clouds. Here we investigate the neutrino production in AT2019dsg by examining the TDE outflow-cloud interaction model. We find that, for an outflow with a velocity of 0.07c and a kinetic luminosity of $10^{45}\rm erg\ s^{-1}$, protons may be accelerated up to $\sim$ 60 PeV by the bow shocks, and generate PeV neutrinos by interactions with clouds. The predicted neutrino number in this model depends on the uncertainties of model parameters and in order to match the observations, some challenging values of parameters have been involved. The PeV neutrino event number can be $\sim 4\times10^{-3}$ for a hard proton index $\Gamma=1.5$.