This work is based on [15]. T.O. and D.R. would like to thank the University of Groningen for hospitality. E.B. and T.O. are supported by the European Commission FP6 program MRTN- CT-2004-005104 in which E.B. and J.H. are associated to Utrecht university and T.O. is associated to the IFT-UAM/CSIC in Madrid. The work of E.B., J.H. and T.O. is partially supported by the Spanish grant BFM2003-01090. The work of T.O. has been partially supported by the Comunidad de Madrid grant HEPHACOS P-ESP-00346. Part of this work was completed while D.R. was a post-doc at King's College London, for which he would like to acknowledge the PPARC grant PPA/G/O/2002/00475. In addition, he is presently supported by the European EC-RTN project MRTN-CT-2004-005104, MCYT FPA 2004-04582-C02-01 and CIRIT GC 2005SGR-00564. J.H. is supported by a RUG breedtetrategie grant.

We re-investigate the construction of half-supersymmetric seven-brane solutions of IIB supergavity. In contrast to previous approaches we allow the occurrence of objects with monodromy Tr Λ ≠ 2. We obtain non-trivial information from the requirement of a globally well-defined Killing spinor and by including SL(2,Z)-invariant source terms.

10 páginas, 2 figuras, 1 tabla.-- El PDF es el artículo en su versión pre-print.

Peer reviewed