We have presented the first results of an observational program devoted to the measure of cluster redshifts and velocity dispersions. At the present stage of this work, estimates of the velocity dispersions have to be considered as preliminary results as a consequence of the small number of measured redshifts per cluster. As a second step, we are carrying on further spectroscopical observations with multi-object facilities in order to increase efficiently the data for each cluster. The information which can be derived from these data is of course useful for various studies, from large-scale structure to cluster dynamics. Our main aim is to use this database to constrain the parameters defining the cluster fundamental plane.
Acknowledgements
We would like to thank all the staff of the Observatoire de Haute Provence for their efficient assistance during the successive observational runs. S.M. would like to thank Véronique Cayatte, Catherine Boisson and Philippe Prugniel for fruitful discussions. We are grateful to Jean Guibert and the MAMA team for their scans of the POSSII plates. This research has made use of the NASA/IPAC extragalactic database (NED) which is operated by the Jet Propulsion Laboratory, Caltech, under contract with the National Aeronautics and Space Administration.