Journal ArticleDOI
The polarization of decimetric pulsations
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In this article, a sample of 10 decimetric broadband pulsations were observed in 1980-1983 and analyzed in polarization, and the high circular polarization was interpreted to be determined by the emission mechanism itself, not by propagation effects or cut-offs (contrary to the metric type I noise storms).Abstract:
A sample of 10 decimetric broadband pulsations were observed in 1980–1983 and analyzed in polarization. Half of the data set was 85–100% circularly polarized, the other half showed a mild polarization of 15–55%. The polarization is constant in time and frequency for the strongly polarized group. All the mildly polarized bursts originate from near the limb; the lower degree of circular polarization is likely to be caused by depolarization due to propagation effects. The degree of polarization is constant throughout the event, but varies in frequency for the mild polarized group. Following the leading spot hypothesis, the magneto-ionic mode of the emission was found to be extraordinary. The high circular polarization of the pulsations was interpreted to be determined by the emission mechanism itself, not by propagation effects or cut-offs (contrary to the metric type I noise storms). Implications for pulsation models are discussed.read more
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Journal ArticleDOI
Coronal Loop Oscillations Observed with the Transition Region and Coronal Explorer
TL;DR: In this article, spatial oscillations of coronal loops were detected in extreme-ultraviolet wavelengths (171 with the T ransition Region and Coronal Explorer, in the tem- Ae ) perature range of MK.
Book ChapterDOI
Theory of Radio Pulsations in Coronal Loops
TL;DR: In this paper, various versions of pulsation models are reviewed and classified in three groups according to their driver mechanisms: (1) Magnetic flux tube oscillations (the emissivity of trapped particles is modulated by a standing or propagating MHD wave), (2) cyclic self-organizing systems of plasma instabilities (wave-particle, wave-wave interactions), and (3) modulation of acceleration (acceleration/injection of particles into the source).
Journal ArticleDOI
Magnetohydrodynamic Sausage-Mode Oscillations in Coronal Loops
TL;DR: In this article, the authors revisited previous observations that have been interpreted in terms of MHD sausage-mode oscillations in coronal loops and come to the following conclusions: (1) fast sausage MHDmode oscillation requires such a high electron density imposed by the wavenumber cutoff that they can only occur in flare loops, and (2) in the previously reported radio observations (ν ≈ 100 MHz to 1 GHz) with periods of P ≈ 0.5-5 s, the fast-sausage MHD oscillation is likely to be confined
Journal ArticleDOI
Observable Parameters of Solar Microwave Pulsating Structure and Their Implications for Solar Flare
TL;DR: In this article, a set of observable parameters including emission frequency (f0), bandwidth (bw), polarization degree (r), period (P), duration (D), modulation depth (M), quality factor (Q), single pulse frequency drifting rate (Rspfd), global frequency drifting rates (Rgfd), and symmetrical factor of the pulse profile (S) were defined.
Journal ArticleDOI
VLA and Trieste observations of type I storms, type IV and pulsations
TL;DR: In this article, the authors used the Trieste Astronomical Observatory records at 327 MHz to determine whether type I or IV sources at 333 MHz contain features of small (arcsec) scale.
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Journal ArticleDOI
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TL;DR: In this paper, the results of a search for fast spikes in 2830 hard X-ray solar flares as observed with the hard Xray burst spectrometer on the Solar Maximum Mission (SMM) are presented.
Journal ArticleDOI
Regular Pulses from the Sun and a Possible Clue to the Origin of Solar Cosmic Rays
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Journal ArticleDOI
Acceleration and confinement of energetic particles in the 1980 June 7 solar flare
TL;DR: In this article, the temporal evolution of the X-ray and radio spectra and the polarization and spatial structure of the microwave source have been examined, and the following interpretation is found to be consistent with the observations: (1) the variations in the electron acceleration/injection spectrum are responsible for the observed variations in hard Xray and microwave emissions, and (2) the locations of the hard X ray and microwave sources are probably different, the Xray source being located at a lower altitude.
Journal ArticleDOI
Pulsations of type IV solar radio emission: The bounce-resonance effects
TL;DR: In this article, a mechanism of excitation of radial oscillations of a "magnetic tube" was proposed for the interpretation of a periodic modulation of type IV radio burst intensity in the meter and decimeter range.