Details

Autor(en) / Beteiligte

• Bienaymé, O.
• Robin, A. C.
• Famaey, B.

Titel

Quasi integral of motion for axisymmetric potentials

Ist Teil von

• Astronomy and astrophysics (Berlin), 2015-09, Vol.581, p.1-9

Ort / Verlag

EDP Sciences

Erscheinungsjahr

2015

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• We present an estimate of the third integral of motion for axisymmetric three-dimensional potentials. This estimate is based on a Stäckel approximation and is explicitly written as a function of the potential. We tested this scheme for the Besançon Galactic model and two other disc-halo models and find that orbits of disc stars have an accurately conserved third quasi integral. The accuracy ranges from of 0.1% to 1% for heights varying from z = 0 kpc to z = 6 kpc and Galactocentric radii R from 5 to 15 kpc. We also tested the usefulness of this quasi integral in analytic distribution functions of disc stellar populations: we show that the distribution function remains approximately stationary and that it allows to recover the potential and forces by applying Jeans equations to its moments.