An Halpha study of the kinematics of NGC 3627

Laurent Chemin (1, 2) , Véronique Cayatte (1, 2) , Chantal Balkowski (1, 2) , M. Marcelin (3) , Philippe Amram (3) , Willem van Driel (1, 2) , Hector Flores (1, 2)

1 GEPI - Galaxies, Etoiles, Physique, Instrumentation
2 Physique des Galaxies et Cosmologie
3 OAMP - Observatoire Astronomique de Marseille Provence

We report here on the first observations in the Halpha-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{Regan3}). 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 degr relative to the inner parts of the galaxy.

Domaines: Astrophysique [astro-ph]

Laurent Chemin, Véronique Cayatte, Chantal Balkowski, M. Marcelin, Philippe Amram, et al.. An Halpha study of the kinematics of NGC 3627. Astronomy and Astrophysics - A&A, 2003, 405, pp.89-97. ⟨10.1051/0004-6361:20030590⟩. ⟨hal-03786639⟩