Steepened magnetosonic waves in the high. beta. plasma surrounding Comet Giacobini-Zinner
We extend the previous studies of intense hydromagnetic waves at Giacobini-Zinner to investigate the mode and direction of wave propagation. Simultaneous high-resolution measurements of electron density fluctuations demonstrate that the long period (approx.100 s) waves are propagating in the magnetosonic mode. Principal axis analyses of the long period waves and accompanying partial rotations show that the sum of the wave phase rotations is 360/sup 0/C, indicating that both are parts of the same wave oscillation. From the time sequence of the steepened waveforms observed by ICE, we demonstrate that the waves must propagate towards the sun with C/sub ph/ < V/sub sw/. All available observations are consistent with wave generation by the resonant ion ring or ion beam instability which predicts right-hand polarized waves propagating in the ion beam (solar) direction. The large amplitudes ..delta.. polarized B/absolute value of Bapprox.0(1) and small scale sizes (rotational discontinuities) of the cometary waves suggest that rapid pitch-angle scattering and energy transfer with energetic ions should occur. Since the waves are highly compressive, ..delta.. absolute value of B/absolute value of B = 0(0.5), one can also anticipate first-order Fermi acceleration. 15 refs., 6 figs.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); California Institute of Technology (CalTech), Pasadena, CA (United States). Jet Propulsion Lab. (JPL); California Univ., Los Angeles (USA). Dept. of Atmospheric Sciences; Kyoto Univ. (Japan)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 7192983
- Report Number(s):
- LA-UR-87-38; CONF-8610207-8; ON: DE87005123
- Resource Relation:
- Conference: 20. ESLAB symposium, Heidelberg, F.R. Germany, 27 Oct 1986; Other Information: Microfiche only, copy does not permit paper copy reproduction
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
COMETS
MAGNETOACOUSTIC WAVES
DENSITY
ELECTRONS
PLASMA INSTABILITY
POLARIZATION
SOLAR WIND
ELEMENTARY PARTICLES
FERMIONS
HYDROMAGNETIC WAVES
INSTABILITY
LEPTONS
PHYSICAL PROPERTIES
SOLAR ACTIVITY
640107* - Astrophysics & Cosmology- Planetary Phenomena