Search Publications
ALMA and ROSINA detections of phosphorus-bearing molecules: the interstellar thread between star-forming regions and comets
Altwegg, K.; Balsiger, H.; Berthelier, J. J. +20 more
To understand how phosphorus (P)-bearing molecules are formed in star-forming regions, we have analysed the Atacama Large Millimeter/Submillimeter Array (ALMA) observations of PN and PO towards the massive star-forming region AFGL 5142, combined with a new analysis of the data of the comet 67P/Churyumov-Gerasimenko taken with the Rosetta Orbiter S…
How comets work: nucleus erosion versus dehydration
Blum, J.; Güttler, C.; Gundlach, B. +3 more
We develop an activity model based on ice sublimation and gas diffusion inside cm-sized pebbles making-up a cometary nucleus. Our model explains cometary activity assuming no free parameters and fixing the nucleus surface temperature Ts, its gradient below the nucleus surface at thermal equilibrium, the pressure inside the porous pebble…
The gas production of 14 species from comet 67P/Churyumov-Gerasimenko based on DFMS/COPS data from 2014 to 2016
Altwegg, Kathrin; Rubin, Martin; Läuter, Matthias +1 more
The coma of comet 67P/Churyumov-Gerasimenko has been probed by the Rosetta spacecraft and shows a variety of different molecules. The ROSINA COmet Pressure Sensor and the Double Focusing Mass Spectrometer provide in situ densities for many volatile compounds including the 14 gas species H2O, CO2, CO, H2S, O2
On the activity of comets: understanding the gas and dust emission from comet 67/Churyumov-Gerasimenko's south-pole region during perihelion
Blum, J.; Fulle, M.; Gundlach, B.
When comets approach the Sun, their surface is heated and the volatile species start to sublimate. Due to the increasing gas pressure, dust is ejected off the surface, which can be observed as cometary coma, dust tail, and trail. However, the underlying physical processes are not fully understood. Using state-of-the-art results for the transport o…
Molecule-dependent oxygen isotopic ratios in the coma of comet 67P/Churyumov-Gerasimenko
Altwegg, K.; Balsiger, H.; Fuselier, S. A. +9 more
The ratios of the three stable oxygen isotopes 16O, 17O, and 18O on the Earth and, as far as we know in the Solar system, show variations on the order of a few per cent at most, with a few outliers in meteorites. However, in the interstellar medium there are some highly fractionated oxygen isotopic ratios in some s…
Average cometary ion flow pattern in the vicinity of comet 67P from moment data
Nilsson, Hans; Behar, Etienne; Goetz, Charlotte +7 more
Average flow patterns of ions around comet 67P detected by the RPC-ICA instrument onboard Rosetta are presented both as a time series and as a spatial distribution of the average flow in the plane perpendicular to the comet - Sun direction (Y-Z plane in the coordinate systems used). Cometary ions in the energy range up to 60 eV flow radially away …
First in situ detection of the CN radical in comets and evidence for a distributed source
Altwegg, Kathrin; Hänni, Nora; Rubin, Martin +4 more
Although the debate regarding the origin of the cyano (CN) radical in comets has been ongoing for many decades, it has yielded no definitive answer to date. CN could previously only be studied remotely, strongly hampering efforts to constrain its origin because of very limited spatial information. Thanks to the European Space Agency's Rosetta spac…
The interior of Comet 67P/C-G; revisiting CONSERT results with the exact position of the Philae lander
Kofman, Wlodek; Herique, Alain; Rogez, Yves +3 more
CONSERT, a bistatic radar onboard the Rosetta spacecraft and its Philae lander, was designed to probe the nucleus of comet 67P/Churyumov-Gerasimenko with radio waves at 90 MHz frequency. In 2016 September, the exact position of Philae was retrieved, within the region previously identified by CONSERT. This allowed us to revisit the measurements and…
67P/Churyumov-Gerasimenko's dust activity from pre- to post-perihelion as detected by Rosetta/GIADA
Fulle, M.; Güttler, C.; Tubiana, C. +18 more
We characterized the 67P/Churyumov-Gerasimenko's dust activity, by analysing individual dust particle velocity and momentum measurements of Grain Impact Analyser and Dust Accumulator (GIADA), the dust detector onboard the ESA/Rosetta spacecraft, collecting dust from tens to hundreds of kilometres from the nucleus. Specifically, we developed a proc…
Near-perihelion activity of comet 67P/Churyumov-Gerasimenko. A first attempt of non-static analysis
Keller, H. U.; Mottola, S.; Hartogh, P. +1 more
The observed rate of water production of comet 67P/Churyumov-Gerasimenko near its perihelion can be approximated by a very steep power function of the heliocentric distance. Widely used thermophysical models based on a static dust layer on top of the icy/refractory matrix are poorly consistent with these observations. We analyse published model re…