1. Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str 1, D-85748 Garching, Germany
2. Physik Department, Technische Universität München, James-Franck-Str 1, D-85748 Garching, Germany
3. Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
4. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
5. Department of Physics, Columbia University, New York, NY 10027, USA
6. Embry Riddle University, 3700 Willow Creek Road, Prescott, AZ 86301, USA