skip to main content

SciTech ConnectSciTech Connect

Title: FREQUENCY DEPENDENCE OF POLARIZATION OF ZEBRA PATTERN IN TYPE-IV SOLAR RADIO BURSTS

We investigated the polarization characteristics of a zebra pattern (ZP) in a type-IV solar radio burst observed with AMATERAS on 2011 June 21 for the purpose of evaluating the generation processes of ZPs. Analyzing highly resolved spectral and polarization data revealed the frequency dependence of the degree of circular polarization and the delay between two polarized components for the first time. The degree of circular polarization was 50%–70% right-handed and it varied little as a function of frequency. Cross-correlation analysis determined that the left-handed circularly polarized component was delayed by 50–70 ms relative to the right-handed component over the entire frequency range of the ZP and this delay increased with the frequency. We examined the obtained polarization characteristics by using pre-existing ZP models and concluded that the ZP was generated by the double-plasma-resonance process. Our results suggest that the ZP emission was originally generated in a completely polarized state in the O-mode and was partly converted into the X-mode near the source. Subsequently, the difference between the group velocities of the O-mode and X-mode caused the temporal delay.
Authors:
; ; ;  [1] ;  [2]
  1. Planetary Plasma and Atmospheric Research Center, Tohoku University, Sendai, Miyagi 980-8578 (Japan)
  2. National Institute of Information and Communications Technology, 4-2-1, Nukui-Kitamachi, Koganei, Tokyo 184-8795 (Japan)
Publication Date:
OSTI Identifier:
22518921
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 808; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CORRELATIONS; FREQUENCY DEPENDENCE; PLASMA; POLARIZATION; RESONANCE; SOLAR RADIO BURSTS; SUN; VELOCITY