1. Laboratory for Astrophysics, Leiden Observatory University Leiden Einsteinweg 55 2333 CA Leiden, The Netherlands
2. Lehrstuhl Technische Thermodynamik Fakultät für Maschinenbau Universität Paderborn Warburger Str. 100 33098 Paderborn Germany
3. Institute for Molecules and Materials, FELIX Laboratory Radboud University Nijmegen Toernooiveld 7 6525 ED Nijmegen, The Netherlands
4. University of Amsterdam 1098 XH Amsterdam The Netherlands
5. Laboratory for Atmospheric and Space Physics University of Colorado Boulder, Colorado 80303 USA
6. Department of Chemistry University of Colorado Boulder, Colorado 80309 USA
7. Institute for Modeling Plasma Atmospheres and Cosmic Dust (IMPACT), NASA/SSERVI Boulder, Colorado 80309 USA