Resonant relaxation and the warp of the stellar disc in the Galactic centre

TL;DR

This paper demonstrates that the observed warp in the young stellar disc at the Galactic centre can naturally result from vector resonant relaxation with the surrounding old stellar cluster, explained through an analytical model.

Contribution

The study introduces an analytical model based on Laplace-Lagrange theory showing that warps in stellar discs can arise naturally from vector resonant relaxation.

Findings

Warp in the stellar disc can be explained by resonant relaxation.

Analytical model successfully reproduces observed warp angles.

Resonant relaxation is a key process in disc dynamics.

Abstract

Observations of the spatial distribution and kinematics of young stars in the Galactic centre can be interpreted as showing that the stars occupy one, or possibly two, discs of radii ~0.05-0.5 pc. The most prominent (`clockwise') disc exhibits a strong warp: the normals to the mean orbital planes in the inner and outer third of the disc differ by ~60 deg. Using an analytical model based on Laplace-Lagrange theory, we show that such warps arise naturally and inevitably through vector resonant relaxation between the disc and the surrounding old stellar cluster.