A Recent Lindblad Resonance in the Solar Neighbourhood

TL;DR

This paper analyzes the velocity substructure of stars in the solar neighborhood, revealing that the Hyades stream's kinematic properties are consistent with scattering at an inner Lindblad resonance, supporting the idea of transient spiral patterns.

Contribution

It provides evidence linking the Hyades stream to an inner Lindblad resonance, suggesting spiral patterns are recurrent and short-lived in the galaxy.

Findings

Hyades stream stars show resonance characteristics

Supports transient spiral pattern hypothesis

Resonance scattering explains velocity substructure

Abstract

Stars in the solar neighbourhood do not have a smooth distribution of velocities. Instead, the distribution of velocity components in the Galactic plane manifests a great deal of kinematic substructure. Here I present an analysis in action-angle variables of the Geneva-Copenhagen survey of ~14,000 nearby F & G dwarfs with distances and full space motions. I show that stars in the so-called "Hyades stream" have both angle and action variables characteristic of their having been scattered at an inner Lindblad resonance of a rotating disturbance potential. This discovery seems to favour spiral patterns as recurrent, short-lived instabilities.