Deviation in stellar trajectory induced by asymmetry in partial tidal disruption

TL;DR

This paper investigates how partial tidal disruption by black holes causes deviations in stellar core trajectories, highlighting the effects of asymmetry, proximity, and mass ratio on observable deviations.

Contribution

It provides a quantitative analysis of orbital dynamics post-partial disruption using hydrodynamical simulations, emphasizing the role of asymmetry and mass ratio.

Findings

Higher deviations occur at lower pericentre distances.

Greater asymmetry in tidal tails increases trajectory deviations.

Observable deviations are limited to mass ratios q ≲ 10^3.

Abstract

We study partial tidal disruption and present a quantitative analysis of the orbital dynamics of the remnant self-bound core. We perform smoothed particle hydrodynamical simulations to show that partial disruption of a star due to the tidal field of a black hole leads to a jump in the specific orbital energy and angular momentum of the core. It directly leads to deviation in the core's trajectory apart from getting a boost in its velocity. Our analysis shows that the variations in the specific orbital energy and angular momentum are higher when the pericentre distance is lower. We conclude that higher mass asymmetry of the two tidal tails increases the magnitude of the trajectory deviations. Our study reveals that observable deviations are only possible when mass ratio $q \lesssim 10^3 $, which indicates the range of intermediate-mass black holes.