Ion Acoustic Waves Observed at Comet 67P/Churyumov-Gerasimenko

Herbert Gunell1, Hans Nilsson2, Maria Hamrin3, Anders Eriksson4, Romain Maggiolo1, Pierre Henri5, Kathrin Altwegg6, Chia-yu Tzou6, Martin Rubin7, Karl-Heinz Glassmeier8, Gabriella Stenberg Wieser2, Cyril Simon Wedlund9, Johan De Keyser10, Frederik Dhooghe10, Gaël Cessateur10 and Andrew Gibbons1, (1)Belgian Institute for Space Aeronomy, Brussels, Belgium, (2)IRF Swedish Institute of Space Physics Kiruna, Kiruna, Sweden, (3)Umeå University, Department of Physics, Umeå, Sweden, (4)IRF Swedish Institute of Space Physics, Uppsala, Sweden, (5)Université d'Orléans, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Orléans, France, (6)University of Bern, Physikalisches Institut, Bern, Switzerland, (7)University of Bern, Physics Institute, Space Research and Planetary Sciences, Bern, Switzerland, (8)Institute of Geophysics and extraterrestrial Physics, Technical University of Braunschweig, Braunschweig, Germany, (9)University of Oslo, Department of Physics, Oslo, Norway, (10)Belgisch Instituut voor Ruimte-Aeronomie, Brussel, Belgium