1. ESO, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München, Germany
2. Excellence Cluster Universe, Boltzmannstr 2, D-85748, Garching, Germany
3. Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
4. Dr. Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics, Universität Erlangen-Nürnberg, Sternwartstr 7, 96049 Bamberg, Germany
5. NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA