Simulated optical light curves of super-Eddington tidal disruption events with ZEBRA flows

TL;DR

This paper simulates optical light curves of super-Eddington tidal disruption events using the ZEBRA flow model, comparing results with observations and discussing model refinements to better understand these energetic phenomena.

Contribution

It introduces detailed simulated light curves based on the ZEBRA model and compares them with observed TDEs, highlighting areas for model improvement.

Findings

ZEBRA model accurately captures super-Eddington timescales and luminosity.

Optical emission from accretion flow dominates jet emission.

Model deviations suggest the inflating disc is more rapid than predicted.

Abstract

We present simulated optical light curves of super-Eddington tidal disruption events (TDEs) using the zero-Bernoulli accretion (ZEBRA) flow model, which proposes that during the super-Eddington phase, the disc is quasi-spherical, radiation-pressure dominated, and accompanied by the production of strong jets. We construct light curves for both on- and off-axis (with respect to the jet) observers to account for the anisotropic nature of the jetted emission. We find that at optical wavelengths, emission from the accretion flow is orders of magnitude brighter than that produced by the jet, even with boosting from synchrotron self-Compton. Comparing to the observed jetted TDE Swift J2058.4+0516, we find that the ZEBRA model accurately captures the timescale for which accretion remains super-Eddington and reproduces the luminosity of the transient. However, we find the shape of the light curves deviate at early times and the radius and temperature of our modelled ZEBRA are $\sim2.7 - 4.1$ times smaller and $\sim1.4 - 2.3$ times larger, respectively, than observed. We suggest that this indicates the ZEBRA inflates more, and more rapidly, than currently predicted by the model, and we discuss possible extensions to the model to account for this. Such refinements, coupled with valuable new data from upcoming large scale surveys, could help to resolve the nature of super-Eddington TDEs and how they are powered.