Affiliation: | X-Ray and Observational Astronomy Group, Department of Physics &Astronomy, University of Leicester, Leicester LE1 7RH;Department of Physics, University of Durham, South Road, Durham DH1 3LE;Laboratory for High Energy Astrophysics, Code 662, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA;Institut für Astronomie und Astrophysik –Astronomie, Sand 1, 72076 Tübingen, Germany |