A new method for the determination of action integrals in the study of galactic dynamics

Understand

Action-angle coordinates are an essential tool for understanding the properties of the six dimensional phase space involved in orbits of stars in galactic potentials.

• A new method, which does not require specific knowledge of a generating function, is described, implemented and tested that calculates the actions of an orbit in an arbitrary potential of an integrable Hamiltonian given a set of Cartesian phase space points.
• The method chooses between the simple harmonic oscillator and isochrone potentials to fit the data using a Levenberg-Marquardt routine.
• An average is taken over the angle coordinates by calculating volumes in phase space using the metric free FiEstAS algorithm.