3D spectroscopy with VLT/GIRAFFE
I. The true Tully Fisher relationship at z 0.6
Laboratoire Galaxies Etoiles Physique et Instrumentation, Observatoire de Paris-Meudon, 5 place Jules Janssen, 92195 Meudon Cedex, France e-mail: firstname.lastname@example.org
2 Observatoire Astronomique Marseille-Provence & Laboratoire d'Astrophysique de Marseille, 2 place Le Verrier, 13248 Marseille Cedex 04, France
Accepted: 22 February 2006
A precise derivation of the evolution of the Tully Fisher is crucial to understand the interplay between dark matter and baryonic matter in cosmological models, using 15 deployable integral field units of FLAMES/GIRAFFE at VLT, we have recovered the velocity fields of 35 galaxies at intermediate redshift (). This facility is able to recover the velocity fields of almost all the emission line galaxies with and Å. In our sample, we find only 35% rotating disks. These rotating disks produce a Tully-Fisher relationship (stellar mass or MK versus ) which has apparently not evolved in slope, zero point and scatter since . The only evolution found is a brightening of the B band luminosity of a third of the disks, possibly due to an enhancement of the star formation. The very large scatters found in previously reported Tully-Fisher relationships at moderate redshifts are caused by the numerous (65%) galaxies with perturbed or complex kinematics. Those galaxies include minor or major mergers, merger remnants and/or inflow/outflows and their kinematics can be easily misidentified by slit spectroscopy. Their presence suggests a strong evolution in the dynamical properties of galaxies during the last 7 Gyr.
Key words: galaxies: kinematics and dynamics / galaxies: evolution / galaxies: formation
© ESO, 2006