We thank the BeppoSAX Team for contributing to the operations of the satellite and for continuous maintenance of the software. This research has made use of SAXDAS linearized and cleaned event files produced at the BeppoSAX Science Data Center. Financial support from the Italian Space Agency is acknowledged. We thank D.A. Smith who kindly provided us the Ginga spectrum of Mkn 3 and an anonymous referee for detailed and constructive remarks.
© European Southern Observatory (ESO) 1999
Online publication: March 29, 1999