Angle-action variables for orbits trapped at a Lindblad resonance. Issue 1 (19th May 2020)

• Record Type: Journal Article
• Authors: Binney, James
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 495:Issue 1(2020)
• Page Start: 886
• Page End: 894
• Publication Date: 2020-05-19
• Subjects: methods: numerical -- Galaxy: kinematics and dynamics; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa092
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: The conventional approach to orbit trapping at Lindblad resonances via a pendulum equation fails when the parent of the trapped orbits is too circular. The problem is explained and resolved in the context of the Torus Mapper and a realistic Galaxy model. Tori are computed for orbits trapped at both the inner and outer Lindblad resonances of our Galaxy. At the outer Lindblad resonance, orbits are quasi-periodic and can be accurately fitted by torus mapping. At the inner Lindblad resonance, orbits are significantly chaotic although far from ergodic, and each orbit explores a small range of tori obtained by torus mapping.