1. Department of Physics and Astronomy, and LaserLaB, VU University, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
2. Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
3. School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287, USA
4. NASA Astrobiology Institute, NASA Ames Research Center, Moffett Field, California 94035, USA
5. Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
6. Synchrotron Soleil, Orme des Merisiers, St. Aubin, BP 48, 91192 Gif sur Yvette Cedex, France