We wish to thank the referee, Toshiaki Takeshima, for the precise and detailed comments which improved the quality of the paper. We thank, also, the BeppoSAXScientific Data Center staff for their support during the observation and data analysis. SP acknowledges support from CNR PhD grant. This research has been partially funded by the Italian Space Agency.
© European Southern Observatory (ESO) 2000
Online publication: June 5, 2000