Affiliation: | University of Oxford, Department of Astrophysics, Nuclear Physics Building, Keble Road, Oxford OX1 3RH; Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602-2451, USA; Department of Physics, Keele Universtity, Keele, Staffordshire ST5 5BG; Department of Physics and Space Sciences, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901-6988, USA |