Dipolar radiation from spinning dust grains coupled to an electromagnetic wave

A. Guerreiro, M. Eloy, J. T. Mendonça, R. Bingham

Research output: Contribution to journalArticle

Abstract

In this paper we investigate how the complex rotation and quivering motion of an elongated polarized dust grain in the presence of a monochromatic electromagnetic (EM) wave can produce dipolar emission with two distinct spectral components. We present a model for the emission of radiation by elongated polarized dust grains under the influence of both an external EM wave and a constant background magnetic field. The dust, exhibiting rotational motion at the external EM field frequency ω0 as well as quivering motion at a frequency Ω0, proportional to the EM field amplitude, will radiate with frequencies that will depend on the external field wavelength and amplitude. The radiated spectra exhibits a frequency around ω0, and sidebands at ω0 ± ω0 and ω0± 2Ω0. Since the amplitude and the frequency of the background EM field are independent parameters, this model establishes a correlation between different spectral components of galactic dipolar emission, which may help to explain the correlation between a component of the Galactic microwave emission and the 100 μ m thermal emission from interstellar dust that has been recently measured.
Original languageEnglish
Pages (from-to)555-563
Number of pages9
JournalJournal of Plasma Physics
Volume73
Issue number4
Early online date6 Dec 2006
DOIs
Publication statusPublished - Aug 2007

Keywords

  • electromagnetic waves
  • grain size and shape
  • magnetic fields
  • natural frequencies
  • polarization
  • spectrum analysis

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