Periodic orbits in warped disks

Geneva Observatory, University of Geneva, 1290 Sauverny, Switzerland

Corresponding author: Y. Revaz, Yves.Revaz@obs.unige.ch

Received: 22 November 2000
Accepted: 9 April 2001

Abstract

It is often assumed that a warped galaxy can be modeled by a set of rings. This paper verifies numerically the validity of this assumption by the study of periodic orbits populating a heavy self-gravitating warped disk. The phase space structure of a warped model reveals that the circular periodic orbits of a flat disk are transformed in quasi annular periodic orbits which conserve their stability. This lets us also explore the problem of the persistence of a large outer warp. In particular, the consistency of its orbits with the density distribution is checked as a function of the pattern speed.