Isolating the extreme debris disc signature -- explorations of eccentric extreme debris discs formed by giant impacts

TL;DR

This paper models eccentric debris discs formed by giant impacts using simulations, revealing how their morphology and emission vary with impact parameters, and explores their potential as signatures of such impacts.

Contribution

It introduces a detailed simulation approach to study eccentric debris discs and identifies how impact geometry influences observable features.

Findings

Eccentric discs inherit the orbit eccentricity of the impact center of mass.

Impact orientation significantly affects disc morphology and emission.

Eccentricity influences short-term emission variability, relevant for identifying giant impacts.

Abstract

In this work, we used N-body simulations and a radiative transfer package to model the evolution of eccentric debris discs produced by giant impacts between planetary embryos. This included how the morphology and infrared emission of these discs varied with embryo eccentricity and collision true anomaly. We found that eccentric discs inherit the eccentric properties of the centre of mass orbit of the two colliding embryos. However, the orientation of the collision with the respect to this orbit plays a key role in determining how closely the disc material resembles the centre of mass orbit. Additionally, we found that increased eccentricity acted to suppress the formation of certain short-term variations in the disc emission depending on the collision position. These short-term variations have been associated with an observational phenomenon called extreme debris discs. Short-term variability has been suggested as a potential signature for giant impacts.