Patrick.Woudt@uct.ac.za

¹ Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
² Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
³ Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138-1516, USA
⁴ Department of Astrophysics, Radboud University Nijmegen, P.O. Box 9010, 6500 GL, Nijmegen, Netherlands
⁵ Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
⁶ Department of Mathematical Sciences, University of South Africa, UNISA, Pretoria 0003, South Africa
⁷ University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL, UK
⁸ Also at Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138-1516, USA.
⁹ Also at School of Physics and Astronomy, Southampton University, Highfield, Southampton SO17 1BJ, UK.