Source of O mode radio emissions from the dayside of Uranus

Journal Article · Sat Sep 01 00:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA095iA09p15263· OSTI ID:5444866

Menietti, J D; Curran, D B ^[1]

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1. Southwest Research Inst., San Antonio, TX (USA)

During the inbound trajectory toward Uranus the Planetary Radio Astronomy instrument on board the Voyager 2 spacecraft observed narrowband smooth (n-smooth) emission at frequencies centered near 60 kHz and O mode emission (the dayside source) in a frequency range narrowly confined around 160 kHz. By assuming empirical models of the plasma density for the dayside magnetosphere of Uranus, and by using cold plasma theory together with observational constraints, the authors have performed ray-tracing calculations to determine the source lcoation of the O mode emission. The dayside source appears to originate along magnetic field lines with a footprint near the north magnetic pole. Sources of nightside, high-frequency, broadband smooth (b-smooth) emission observed by Voyager after encounter are believed to exist near the conjugate footprint of these same field lines. This would indicate that the particle population supplying the free energy source has energies at least as high as a few keV and the density in the source region satisfies the condition 0.3 < f{sub p}/f{sub ce} < 1.0 where f{sub p} and f{sub ce} are the electron plasma frequency and gyrofrequency, respectively.

• OSTI ID: 5444866
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:A9; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
URANUS PLANET
RADIOWAVE RADIATION
COLD PLASMA
COORDINATES
MAGNETIC FIELDS
MATHEMATICAL MODELS
ORIGIN
PLANETARY MAGNETOSPHERES
PLASMA DENSITY
PLASMA INSTABILITY
POLAR REGIONS
RADIOASTRONOMY
VOYAGER SPACE PROBES
ASTRONOMY
ATMOSPHERES
ELECTROMAGNETIC RADIATION
INSTABILITY
PLANETARY ATMOSPHERES
PLANETS
PLASMA
RADIATIONS
SPACE VEHICLES
VEHICLES
640107* - Astrophysics &amp; Cosmology- Planetary Phenomena