An Hα study of the kinematics of NGC 3627^*

¹ Observatoire de Paris, GEPI, UMR 8111, associé au CNRS et à l'Université Paris VII, 5 place J. Janssen, 92195 Meudon, France
² Observatoire Astronomique Marseille-Provence, 2 place Le Verrier, 13248 Marseille, France

Corresponding author: L. Chemin, Laurent.Chemin@obspm.fr

Received: 24 September 2002
Accepted: 15 April 2003

Abstract

We report here on the first observations in the Hα  line to investigate the kinematics of the spiral galaxy NGC 3627, the brightest member of the Leo Triplet. The velocity field observed at high angular resolution shows signatures of non-circular motion. They can be attributed to dynamical perturbations due to the bar and to external interactions. In particular, we confirm the presence of an inner ring recently detected in CO observations (Regan et al. [CITE]). We find a corotation radius significantly smaller than that derived in previous studies and we show that the inner ring location is consistent with the ultra-harmonic resonance induced by the bar pattern speed. We also show that a warped tilted-ring model can be fitted to the outer parts of the southern, receding half of the disc, which is inclined by some 15° relative to the inner parts of the galaxy.