73 research outputs found
Whistler mode waves and the electron heat flux in the solar wind: Cluster observations
The nature of the magnetic field fluctuations in the solar wind between the
ion and electron scales is still under debate. Using the Cluster/STAFF
instrument, we make a survey of the power spectral density and of the
polarization of these fluctuations at frequencies Hz, during five
years (2001-2005), when Cluster was in the free solar wind. In of
the selected data, we observe narrow-band, right-handed, circularly polarized
fluctuations, with wave vectors quasi-parallel to the mean magnetic field,
superimposed on the spectrum of the permanent background turbulence. We
interpret these coherent fluctuations as whistler mode waves. The life time of
these waves varies between a few seconds and several hours. Here we present,
for the first time, an analysis of long-lived whistler waves, i.e. lasting more
than five minutes. We find several necessary (but not sufficient) conditions
for the observation of whistler waves, mainly a low level of the background
turbulence, a slow wind, a relatively large electron heat flux and a low
electron collision frequency. When the electron parallel beta factor
is larger than 3, the whistler waves are seen along the
heat flux threshold of the whistler heat flux instability. The presence of such
whistler waves confirms that the whistler heat flux instability contributes to
the regulation of the solar wind heat flux, at least for 3, in the slow wind, at 1 AU.Comment: The Astrophysical Journal, 2014, in pres
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PARIS-BIUP (751062107) / SudocSudocFranceF
Etude clinique et biologique de patients co-infectés par le VIH et le VHC à l'hôpital Foch
PARIS-BIUP (751062107) / SudocSudocFranceF
Evolution génétique et sensibilité aux antibiotiques des souches de staphylococcus aureus meticillinorésistantes, sensibles à la gentamicine, isolées entre 1991 et 1997
PARIS-BIUP (751062107) / SudocSudocFranceF
Le tenofovir (un nouvel outil antirétroviral)
PARIS-BIUP (751062107) / SudocSudocFranceF
Virus grippaux, grippe saisonnière, grippe aviaire
PARIS-BIUP (751062107) / SudocSudocFranceF
Determination of the electron density fluctuation spectrum in the solar wind using Ulysses observations
International audienc
Determination of the electron density fluctuation spectrum in the solar wind using Ulysses observations
International audienc
Problématique de la prophylaxie du tétanos chez un patient n'ayant pas un statut vaccinal bien défini
PARIS-BIUP (751062107) / SudocSudocFranceF
Bronchiolites aiguës du nourrisson de moins de 6 mois (étude épidémiologique rétrospective au CHG R. Ballanger (Aulnay-sous-Bois) durant l'hiver 1998-1999)
PARIS-BIUP (751062107) / SudocSudocFranceF
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