Quantifying the impact of relativistic precession on tidal disruption event light curves

TL;DR

This study investigates how relativistic precession affects the observable light curves of tidal disruption events, revealing that precession can cause significant delays in peak brightness depending on black hole mass and inclination.

Contribution

It introduces two-dimensional radiation-hydrodynamic simulations to model the impact of relativistic precession on TDE light curves, highlighting effects for different black hole masses and inclinations.

Findings

Precession causes minimal effect for ~10^6 M_sun black holes with no inclination.

High inclination (~90°) black holes of >10^7 M_sun show delayed light curve peaks.

Precession can delay peak brightness by approximately 100 days.

Abstract

The tidal field of a black hole can turn a star into a gas stream whose orbit can precess, especially if the a black hole is rapidly spinning. In this work, we investigate the impact of precession on the light curves of tidal disruption events (TDE). To do so, we perform two-dimensional radiation-hydrodynamic simulations of the interaction of the TDE wind and luminosity with the precessed stream wrapped around the black hole. Our results show that in events with black holes of $\sim10^6~\text{M}_{\odot}$ and no orbit-spin inclination, the line of sight has little effect on the light curves, since the stream covers a small fraction of the solid angle as the precession is confined to the orbital plane. In the case of black holes of $\gtrsim10^7~\text{M}_{\odot}$ and high inclination ($i\sim90^{\circ}$), the light curve peaks can be delayed by $\sim$100 days due to presence of the precessed stream blocking the radiation in the early phase of the event. We also discuss our efforts to model self-consistently the hydrodynamic evolution of a tidal stellar stream on curved spacetimes by the presence of a massive black hole.