AN, ÅH, and PB wish to thank the Swedish National Space Board (Rymdstyrelsen) for extensive support. PB and ÅH also acknowledge partial support by the Swedish National Science Research Council (NFR). TJM acknowledges financial support by the UK Particle Physics and Astronomy Research Council (PPARC). We wish to thank the referee L. Pagani and J. Black for constructive criticism which helped to improve the manuscript. Onsala Space Observatory, the Swedish National Facility for Radio Astronomy, is operated with financial support from NFR and Chalmers University of Technology. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. We also made use of the UMIST RATE95 reaction rate database created at UMIST, Manchester, UK.
© European Southern Observatory (ESO) 2000
Online publication: June 26, 2000