GALAXIES

Equilibrium and rotational support of elliptical galaxies

Ph. Prugniel (1), F. Simien (2)

(1) Observatoire de Haute-Provence, F-04870 Saint Michel l'Observatoire, France
(2) Observatoire de Lyon, F-69561 St-Genis-Laval cedex, France

Astron. and Astrophys. 282, L1-4 (1994)

Abstract

In order to study the contribution of the rotation to the total kinetic energy of elliptical galaxies, we have obtained new rotation curves and velocity dispersion profiles for 34 galaxies selected for their large residuals with respect to the Fundamental Plane. For a sample of 113 galaxies from our new observations and the available literature, we have analyzed these residuals as a function of the rotational support, quantified by the $V(max)/sigma0 parameter.

The contribution of the rotation to the global equilibrium status of elliptical galaxies is detected and is found to be in agreement with a simple prediction based on the virial theorem for isotropic rotators. The addition of a rotation term to the Fundamental-Plane relation extends its validity to fast rotators, with even a marginal decrease in its apparent thickness.

Last revised: 13-nov-1995, PhP prugniel@obs.univ-lyon1.fr