Institution: | (1) Space Sciences Laboratory, University of California, 94720-7450 Berkeley, CA, USA;(2) Present address: Center for Astrophysics, 60 Garden St., 02138 Cambridge, MA, USA;(3) I. Physikalisches Institut, Universität zu Köln, D-50937 Köln, Germany;(4) Physics Department, University of Pittsburgh, 15260 Pittsburgh, PA, USA;(5) Observatoire de la Côte d'Azur, Nice cedex 4, 06304, France |