Continuous injection model for hard X-ray correlated microwave bursts

Solar Physics ◽  
1976 ◽  
Vol 49 (1) ◽  
Author(s):  
Christian M�tzler
Keyword(s):  
X Ray ◽  
Injection Model ◽  
Continuous Injection ◽  
Microwave Bursts

scholarly journals Another Clue About Particle Acceleration in Impulsive Hard X-Ray/Microwave Bursts

1994 ◽  
Vol 142 ◽  
pp. 697-700
Author(s):  
David Batchelor
Keyword(s):  
Thermal Conduction ◽  
Microwave Emission ◽  
Spectral Information ◽  
Acceleration Of Particles ◽  
X Rays ◽  
Radio Radiation ◽  
X Ray ◽  
Structure And Dynamics ◽  
Source Structure ◽  
Microwave Bursts

AbstractIn a sample of impulsive bursts with rise times less than 30 s, a correlation between burst rise times and the frequency of maximum microwave emission has been found. The implications for source structure and dynamics are discussed in this paper. Previously evidence was found that such bursts are caused by some propagating disturbance such as a shock wave or thermal conduction front. Combining that evidence with the microwave and hard X-ray spectral information suggests that the most rapid bursts are emitted from the most compact and intensely magnetized sources. The most rapid bursts also exhibited the hardest X-ray spectra, as published previously. These facts are important clues to understanding the physical process responsible for impulsive bursts. A model for the bursts is suggested, based on the observations and inferences described.Subject headings: acceleration of particles — Sun: radio radiation — X-rays: bursts

scholarly journals Solar Flare X-Ray Measurements and Their Relation to Microwave Bursts

1975 ◽  
Vol 68 ◽  
pp. 283-297 ◽  
Author(s):  
L. D. De Feiter
Keyword(s):  
Solar Flare ◽  
Source Region ◽  
X Ray ◽  
Observational Material ◽  
Microwave Bursts

This review discusses the available observational material of solar hard X-ray bursts, their interpretation in terms of a model of the source region and their relation with other flash-phase phenomena, in particular the impulsive microwave bursts.

scholarly journals An Observed Correlation Between the Flux Densities of Extended Hard X-ray and Microwave Solar Bursts

1980 ◽  
Vol 86 ◽  
pp. 281-283
Author(s):  
R. T. Stewart ◽  
G. J. Nelson
Keyword(s):  
Second Phase ◽  
Acceleration Process ◽  
X Rays ◽  
Turnover Frequency ◽  
Thin Target ◽  
X Ray ◽  
Time Profiles ◽  
Solar Bursts ◽  
Phase Acceleration ◽  
Microwave Bursts

Crannell et al. (1978) have reported an observed correlation between the time profiles and flux densities of impulsive hard x-ray and microwave solar bursts. We report here on a significant correlation between the fluxes of extended bursts of hard x-rays and microwaves. The significance of our observations follows from the suggestion of Wild, Smerd and Weiss (1963) that the extended bursts are evidence for a second phase acceleration process in the corona. We show that the observed characteristics of these extended microwave bursts (viz. rather a flat spectrum below a turnover frequency which is independent of intensity) can be explained by gyrosynchrotron radiation from the same population of energetic (E ~ 100 keV) electrons as those emitting thin-target x-ray bremsstrahlung.

scholarly journals On the Thermalisation of Flare-Time Energetic Electrons Observed at Radio and X-Ray Wavelengths

1980 ◽  
Vol 91 ◽  
pp. 223-226
Author(s):  
S. S. Degaonkar ◽  
H. S. Sawant ◽  
R. V. Bhonsle
Keyword(s):  
Solar Flare ◽  
Energetic Electrons ◽  
Gradual Rise ◽  
X Ray ◽  
Slow Decay ◽  
Microwave Burst ◽  
Long Duration ◽  
Microwave Bursts

An interesting microwave event at 2800 MHz was recorded at Ahmedabad on September 19, 1977 at 1026 UT at the same time as the H-Alpha solar flare of importance 3B. The microwave burst was of impulsive nature, with as many as twenty impulses in seventy minutes with a quasi-periodicity of 1 to 5 minutes. An X-ray burst recorded by GOES Satellite in 1-8A band showed at the same time a smooth soft X-ray profile with apparently no sign of hard X-ray bursts. This indicates that the acceleration of discrete electron streams which produced impulsive microwave bursts was not sufficient to produce the hard X-ray component but got thermalised to produce soft X-ray emission, with a gradual rise and a slow decay covering a long duration of more than 2 1/2 hours.

scholarly journals Eruption of a Twisted Filament and Associated Phenomena

1998 ◽  
Vol 167 ◽  
pp. 338-341
Author(s):  
Wahab Uddin ◽  
V.K. Verma
Keyword(s):  
Solar Flare ◽  
Geomagnetic Storms ◽  
Magnetic Energy ◽  
Radio Bursts ◽  
X Ray ◽  
Filament System ◽  
Long Duration ◽  
Major Flare ◽  
Ccd Observations ◽  
Microwave Bursts

AbstractIn this paper we present CCD observations between February 14–20, 1994 and analysis of the giant twisted filament evolved in the active region NOAA 7671. The dynamic eruption of the filament was accompanied by a major flare (3B/M4), CME, long duration type II, IV radio bursts, great microwave bursts, a long duration soft X-ray burst, SIDs, strong geomagnetic storms and a very energetic proton flare. We analysed and estimated the twist, length, volume, mass and energy associated with filament system between February 14 and 20, 1994. The present study shows that the magnetic energy required for the solar flare came from the filament system associated with the solar flare and associated phenomena.

scholarly journals Correlation of near-Earth proton enhancements >100 MeV with parameters of solar microwave bursts

2017 ◽  
Vol 3 (3) ◽  
pp. 3-14
Author(s):  
Виктор Гречнев ◽  
Victor Grechnev ◽  
Валентин Киселев ◽  
Valentin Kiselev ◽  
Наталия Мешалкина ◽  
...  
Keyword(s):  
Total Duration ◽  
Correlation Coefficients ◽  
High Energy ◽  
Acceleration Process ◽  
X Ray ◽  
High Energies ◽  
Earth Environment ◽  
Peak Flux ◽  
Solar Microwave ◽  
Microwave Bursts

We analyze the relations between various combinations of peak fluxes and fluences of solar microwave bursts at 35 GHz recorded with the Nobeyama Radio Polarimeters during 1990–2015, and corresponding parameters of proton enhancements with E>100 MeV exceeding 0.1 pfu registered by GOES monitors in near-Earth environment. The highest correlation has been found between the microwave and proton fluences. This fact reflects a dependence of the total number of protons on the total duration of the acceleration process. In the events with strong flares, the correlation coefficients of proton fluences with microwave and soft X-ray fluences are higher than those with speeds of coronal mass ejections. The results indicate a statistically larger contribution of flare processes to acceleration of high-energy protons. Acceleration by shock waves seems to be less important at high energies in events associated with strong flares, although its contribution probably prevails in weaker events. The probability of a detectable proton enhancement was found to directly depend on the peak flux and duration of the microwave burst, that can be used for diagnostics of proton enhancements based on microwave observations.

scholarly journals Correlation of near-Earth proton enhancements >100 MeV with parameters of solar microwave bursts

2017 ◽  
pp. 3-12
Author(s):  
Виктор Гречнев ◽  
Victor Grechnev ◽  
Валентин Киселев ◽  
Valentin Kiselev ◽  
Наталия Мешалкина ◽  
...  
Keyword(s):  
Total Duration ◽  
Correlation Coefficients ◽  
High Energy ◽  
Acceleration Process ◽  
X Ray ◽  
High Energies ◽  
Earth Environment ◽  
Peak Flux ◽  
Solar Microwave ◽  
Microwave Bursts

We analyze the relations between various combinations of peak fluxes and fluences of solar microwave bursts at 35 GHz recorded with the Nobeyama Radio Polarimeters during 1990–2015, and corresponding parameters of proton enhancements with E>100 MeV exceeding 0.1 pfu registered by GOES monitors in near-Earth environment. The highest correlation has been found between the microwave and proton fluences. This fact reflects a dependence of the total number of protons on the total duration of the acceleration process. In the events with strong flares, the correlation coefficients of proton fluences with microwave and soft X-ray fluences are higher than those with speeds of coronal mass ejections. The results indicate a statistically larger contribution of flare processes to acceleration of high-energy protons. Acceleration by shock waves seems to be less important at high energies in events associated with strong flares, although its contribution probably prevails in weaker events. The probability of a detectable proton enhancement was found to directly depend on the peak flux and duration of a microwave burst. This can be used for diagnostics of proton enhancements based on microwave observations.

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