Gunell, H.; Goetz, C.; Eriksson, A.; Nilsson, H.; Simon Wedlund, C.; Henri, P.; Maggiolo, R.; Hamrin, M.; De Keyser, J.; Rubin, Martin; Stenberg Wieser, G.; Cessateur, G.; Dhooghe, F.; Gibbons, A. (2017). Plasma waves confined to the diamagnetic cavity of comet 67P/Churyumov–Gerasimenko. Monthly notices of the Royal Astronomical Society, 469(Suppl_2), S84-S92. Oxford University Press 10.1093/mnras/stx1134
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Ion acoustic waves were observed in the diamagnetic cavity of comet 67P/Churyumov–
Gerasimenko by the Rosetta spacecraft on 2015 August 3, when the comet was 1.25 au
from the Sun. Wave spectra recorded by the Langmuir probe (RPC-LAP), peak near 200 Hz,
decrease for higher frequencies and reach the noise floor at approximately 1.5 kHz. These
waves were observed only when the spacecraft was in the diamagnetic cavity or at its boundary, which is identified as a sharp drop in magnetic field magnitude, measured by RPC-MAG. The plasma, on both sides of the boundary, is dominated by a cold (a few hundred K) water group ion population, one cold (kBTe ~ 0.1 eV) and one warm (kBTe ~ 10 eV) electron population. The observations are interpreted in terms of current-driven ion acoustic waves, generated by currents that flow through bulges on the boundary of the diamagnetic cavity.
Item Type: |
Journal Article (Original Article) |
|---|---|
Division/Institute: |
08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences |
UniBE Contributor: |
Rubin, Martin |
Subjects: |
500 Science > 520 Astronomy 600 Technology > 620 Engineering |
ISSN: |
0035-8711 |
Publisher: |
Oxford University Press |
Language: |
English |
Submitter: |
Dora Ursula Zimmerer |
Date Deposited: |
15 Nov 2017 10:10 |
Last Modified: |
05 Dec 2022 15:07 |
Publisher DOI: |
10.1093/mnras/stx1134 |
BORIS DOI: |
10.7892/boris.105805 |
URI: |
https://boris.unibe.ch/id/eprint/105805 |
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