Affiliation: | Physics Department, Keele University, Keele, Staffordshire ST5 5BG;Gemini Observatory, 670 N. A'ohoku Place, Hilo, HI 96720, USA;Centre for Astrophysics, University of Central Lancashire, Preston, Lancashire PR1 2HE;WE/OBSS, Free University Brussels (VUB), Pleinlaan 2, B-1050 Brussels, Belgium |