1. Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK.
2. Space Science and Technology Department, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK.
3. Laboratory of Molecular Astrophysics, Department of Astrophysics, Centro de Astrobiologia, Instituto Nacional de Tecnicas Aeroespaciales–Consejo Superior de Investigaciones Cientificas, Ctra de Ajalvir, km 4, 28850 Torrejón de Ardoz, Madrid, Spain.
4. School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA, UK.
5. UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK.
6. Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany.
7. Department of Astronomy, Stockholm University, AlbaNova University Center, Roslagstulsbacken 21, 10691 Stockholm, Sweden.
8. Institute for Space Imaging Science, Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada.