% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@ARTICLE{Roussos:824034,
author = {Roussos, E. and Kollmann, P. and Krupp, N. and Paranicas,
C. and Krimigis, S. M. and Mitchell, D. G. and Persoon, A.
M. and Gurnett, D. A. and Kurth, W. S. and Kriegel, H. and
Simon, S. and Khurana, K. K. and Jones, G. H. and Wahlund,
J.-E. and Holmberg, M. K. G.},
title = {{E}nergetic electron observations of {R}hea’s
magnetospheric interaction},
journal = {Icarus},
volume = {221},
number = {1},
issn = {0019-1035},
address = {Orlando, Fla.},
publisher = {Academ. Press},
reportid = {FZJ-2016-06660},
pages = {116 - 134},
year = {2012},
note = {Welcher Autor ist denn vom Forschungszentrum?},
abstract = {Saturn’s moon Rhea is thought to be a simple plasma
absorber, however,energetic particle observations in its
vicinity show a variety ofunexpected and complex interaction
features that do not conform withour current understanding
about plasma absorbinginteractions. Energetic electron data
are especially interesting, asthey contain a series of broad
and narrow flux depletions on eitherside of the moon’s
wake. The association of these dropouts withabsorption by
dust and boulders orbiting within Rhea’s Hill sphere
wassuggested but subsequently not confirmed, so in this
study we reviewdata from all four Cassini flybys of Rhea to
date seeking evidence foralternative processes operating
within the moon’s interactionregion. We focus on energetic
electron observations, which we put incontext with
magnetometer, cold plasma density and energetic iondata. All
flybys have unique features, but here we only focus
onseveral structures that are consistently observed. The
mostinteresting common feature is that of narrow dropouts in
energeticelectron fluxes, visible near the wake flanks.
These are typicallyseen together with narrow flux
enhancements inside the wake. Aphase-space-density analysis
for these structures from the first Rheaflyby (R1) shows
that Liouville’s theorem holds, suggesting that theymay be
forming due to rapid transport of energetic electrons from
themagnetosphere to the wake, through narrow channels. A
series ofpossibilities are considered to explain this
transport process. Weexamined whether complex energetic
electron drifts in the interactionregion of a plasma
absorbing moon (modeled through a hybrid simulationcode) may
allow such a transport. With the exception of
severalfeatures (e.g. broadening of the central wake with
increasing electronenergy), most of the commonly observed
interaction signatures inenergetic electrons (including the
narrow structures) were notreproduced. Additional dynamical
processes, not simulated by thehybrid code, should be
considered in order to explain the data. Forthe small scale
features, the possibility that a flute
(interchange)instability acts on the electrons is discussed.
This instability isprobably driven by strong gradients in
the plasma pressure and themagnetic field magnitude:
magnetometer observations show clearlysignatures consistent
with the (expected) plasma pressure loss due toion
absorption at Rhea. Another potential driver of the
instabilitycould have been gradients in the cold plasma
density, which are,however, surprisingly absent from most
crossings of Rhea’s plasmawake. The lack of a density
depletion in Rhea’s wake suggests thepresence of a local
cold plasma source region. Hybrid plasmasimulations show
that this source cannot be the ionized component ofRhea’s
weak exosphere. It is probably related to
acceleratedphotoelectrons from the moon’s negatively
charged surface, indicatingthat surface charging may play a
very important role in shaping Rhea’smagnetospheric
interaction region.},
ddc = {520},
pnm = {899 - ohne Topic (POF3-899) / Plasma and Dust Simulations
on the Saturnian Rings $(hbs06_20111101)$},
pid = {G:(DE-HGF)POF3-899 / $G:(DE-Juel1)hbs06_20111101$},
typ = {PUB:(DE-HGF)16},
doi = {10.1016/j.icarus.2012.07.006},
url = {https://juser.fz-juelich.de/record/824034},
}