E. Pian (1), P. Romano (2,3), A. Treves (4), G. Ghisellini (2), S.
  Covino (2), A. Cucchiara (5), A. Dolcini (4), G. Tagliaferri (2), C.
  Markwardt (6), S. Campana (2), G. Chincarini (2,3), N. Gehrels (6), P. Giommi
  (7), L. Maraschi (8), S.D. Vergani (9,10), F.M. Zerbi (2), E. Molinari (2),
  V. Testa (11), G. Tosti (12), F. Vitali (11), L.A. Antonelli (11), P. Conconi
  (2), G. Malaspina (2), L. Nicastro (13), E. Palazzi (13), E.J.A. Meurs (9),
  L. Norci (10) ((1) INAF-Trieste, (2) INAF-Brera/Merate, (3) Univ.
  Milano-Bicocca, (4) Univ. Insubria, (5) Penn State, (6) GSFC-NASA, (7) ASI
  ASDC, (8) INAF-Brera/Milano, (9) Dunsink Obs., (10) School of Physical
  Sciences and NCPST, Dublin, (11) INAF-Rome, (12) Univ. Perugia, (13)
  INAF-IASF/Bologna)