Plasma waves confined to the diamagnetic cavity of comet 67P/Churyumov–Gerasimenko

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

Preview

Text watermark.pdf - Published Version Available under License Publisher holds Copyright. Download (2MB) | Preview

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.

Interest & Impact

Downloads

162 since deposited on 15 Nov 2017
13 in the past 12 months

Citations

5 Citations in Web of Science ®
6 Citations in Scopus

Search

in Google Scholar™

Services

Actions (login required)

Edit item

Actions (login required)

Edit item