Spatial distribution of low-energy plasma around 2 comet 67P/CG from Rosetta measurements
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Accepted version
Published Version
Author(s)
Type
Journal Article
Abstract
We use measurements from the Rosetta plasma consortium Langmuir probe and mutual impedance probe to study the spatial distribution of low-energy plasma in the near-nucleus coma of comet 67P/Churyumov-Gerasimenko. The spatial distribution is highly structured with the highest density in the summer hemisphere and above the region connecting the two main lobes of the comet, i.e., the neck region. There is a clear correlation with the neutral density and the plasma to neutral density ratio is found to be ∼1–2·10−6, at a cometocentric distance of 10 km and at 3.1 AU from the Sun. A clear 6.2 h modulation of the plasma is seen as the neck is exposed twice per rotation. The electron density of the collisionless plasma within 260 km from the nucleus falls off with radial distance as ∼1/r. The spatial structure indicates that local ionization of neutral gas is the dominant source of low-energy plasma around the comet.
Date Issued
2015-06-03
Date Acceptance
2015-05-13
Citation
Geophysical Research Letters, 2015, 42 (11), pp.4263-4269
ISSN
1944-8007
Publisher
American Geophysical Union (AGU)
Start Page
4263
End Page
4269
Journal / Book Title
Geophysical Research Letters
Volume
42
Issue
11
Copyright Statement
©2015. American Geophysical Union. All Rights Reserved. This is the peer reviewed version of the following article: Edberg, N. J. T., A. I. Eriksson, E. Odelstad, P. Henri, J.-P. Lebreton, S. Gasc, M. Rubin, M. André, R. Gill, E. P. G. Johansson, F. Johansson, E. Vigren, J. E. Wahlund, C. M. Carr, E. Cupido, K.-H. Glassmeier, R. Goldstein, C. Koenders, K. Mandt, Z. Nemeth, H. Nilsson, I. Richter, G. S. Wieser, K. Szego, and M. Volwerk (2015), Spatial distribution of low-energy plasma around comet 67P/CG from Rosetta measurements. Geophys. Res. Lett., 42, 4263–4269, which has been published in final form at https://dx.doi.org/10.1002/2015GL064233. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving (http://olabout.wiley.com/WileyCDA/Section/id-820227.html#terms).
Publication Status
Published