1. Gemini Observatory, 670 N. A'ohoku Place, Hilo, HI 96720, USA
2. Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637, USA
3. Department of Chemistry, The Enrico Fermi Institute, University of Chicago, Chicago, IL 60637, USA
4. Universitäts-Sternwarte München, 81679, Munich, Germany