Coherent cyclotron maser radiation from UV Ceti

R. Bingham, R.A. Cairns, B.J. Kellett

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

Recent images in the radio of UV Ceti show two intense emission regions above the magnetic poles of the star. The emission is overwhelmingly right hand circularly polarized with 100% right hand polarization at 3 cm and 6 cm wavelengths during flares. This high degree of polarization rules out gyrosynchrotron emission. In this article we propose that such emission can be produced by a coherent cyclotron maser driven by field aligned electrons moving into an increasing magnetic field. Conservation of the first adiabatic invariant causes the electron beam to increase its pitch angle. This produces a broad region on the distribution function and the possibility of producing a positive slope in the perpendicular velocity space. Such distribution functions are common in magnetic mirror type geometries and are possible sources of free energy leading to electromagnetic emission by a cyclotron maser instability mechanism.
LanguageEnglish
Pages1000-1003
Number of pages3
JournalAstronomy and Astrophysics
Volume370
Issue number3
DOIs
Publication statusPublished - May 2001

Fingerprint

masers
cyclotrons
radiation
polarization
distribution functions
magnetic mirrors
magnetic poles
electron
pitch (inclination)
flares
conservation
free energy
electron beams
radio
slopes
electromagnetism
magnetic field
wavelength
geometry
stars

Keywords

  • physical processes
  • polarization
  • radiation mechanisms
  • non-thermal
  • stars
  • flare
  • magnetic fields

Cite this

Bingham, R. ; Cairns, R.A. ; Kellett, B.J. / Coherent cyclotron maser radiation from UV Ceti. In: Astronomy and Astrophysics. 2001 ; Vol. 370, No. 3. pp. 1000-1003.
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Coherent cyclotron maser radiation from UV Ceti. / Bingham, R.; Cairns, R.A.; Kellett, B.J.

In: Astronomy and Astrophysics, Vol. 370, No. 3, 05.2001, p. 1000-1003.

Research output: Contribution to journalArticle

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AU - Cairns, R.A.

AU - Kellett, B.J.

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AB - Recent images in the radio of UV Ceti show two intense emission regions above the magnetic poles of the star. The emission is overwhelmingly right hand circularly polarized with 100% right hand polarization at 3 cm and 6 cm wavelengths during flares. This high degree of polarization rules out gyrosynchrotron emission. In this article we propose that such emission can be produced by a coherent cyclotron maser driven by field aligned electrons moving into an increasing magnetic field. Conservation of the first adiabatic invariant causes the electron beam to increase its pitch angle. This produces a broad region on the distribution function and the possibility of producing a positive slope in the perpendicular velocity space. Such distribution functions are common in magnetic mirror type geometries and are possible sources of free energy leading to electromagnetic emission by a cyclotron maser instability mechanism.

KW - physical processes

KW - polarization

KW - radiation mechanisms

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