EFFECTS OF THE TEMPERATURE ANISOTROPY ON THE MASER INSTABILITY EXCITED BY LOWER ENERGY CUTOFF BEHAVIOR

Journal Article · Tue Feb 01 00:00:00 EST 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/727/2/70· OSTI ID:21567578

Tang, J F; Wu, D J ^[1]

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1. Purple Mountain Observatory, CAS, Nanjing 210008 (China)

The electron-cyclotron maser (ECM) conventionally driven by velocity anisotropies of energetic electrons trapped in magnetic fields is one of the most important radio-emission mechanisms in astrophysics. Recently, Wu and Tang proposed that a proper lower energy cutoff behavior of power-law electrons can effectively excite the ECM emission. This paper considers effects of temperature anisotropy on this new ECM mechanism. The results show that the growth rates of the ECM emissions increase with {beta}{sub perpendicular0} and {beta}{sub ||0}, where {beta}{sub perpendicular0} and {beta}{sub ||0} are the perpendicular and parallel velocity spreads (in units of the light velocity c) of the energetic electron beam, respectively. Moreover, the growth rates of O1 and X2 modes both sensitively depend on the ratio of the electron-cyclotron frequency to the plasma frequency {Omega} and reach their extremum values at {Omega} {approx_equal} 1.5 for the O1 mode and at {Omega} {approx_equal} 1.0 for the X2 mode. Meanwhile, as the mean velocity of the electron beam {beta}{sub s} (in units of c) increases, the growth rate of the O1 mode remains approximately constant and that of the X2 mode decreases considerably.

• OSTI ID: 21567578
• Journal Information: Astrophysical Journal, Vol. 727, Issue 2; Other Information: DOI: 10.1088/0004-637X/727/2/70; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ANISOTROPY
ELECTRON BEAMS
EMISSION
GROWTH
INSTABILITY
MAGNETIC FIELDS
MASERS
SOLAR RADIOWAVE RADIATION
TAIL ELECTRONS
TRAPPED ELECTRONS
VELOCITY
AMPLIFIERS
BEAMS
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
ELECTRONS
ELEMENTARY PARTICLES
EQUIPMENT
FERMIONS
LEPTON BEAMS
LEPTONS
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
PARTICLE BEAMS
RADIATIONS
RADIOWAVE RADIATION
SOLAR RADIATION
STELLAR RADIATION