We would like to thank M. Pérez Gutiérrez for his help with part of the observations. We acknowledge R. Rood, T. Bania and D. Balser for numerous and fruitful discussions on the 3He measurements. We thank the referee for useful comments which improved the content of the paper. The research of F.P., M.T., and D.G has been supported by grant COFIN98-MURST at the Osservatorio di Arcetri. R.B. acknowledges partial funding from Spanish DGES grant PB96-104.
© European Southern Observatory (ESO) 2000
Online publication: March 17, 2000