Another clue about particle acceleration in impulsive hard X-ray/microwave bursts

1994 ◽  
Vol 90 ◽  
pp. 697 ◽  
Author(s):  
David Batchelor
1994 ◽  
Vol 142 ◽  
pp. 697-700
Author(s):  
David Batchelor

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


2014 ◽  
Vol 793 (2) ◽  
pp. 90 ◽  
Author(s):  
Hongjun An ◽  
Kristin K. Madsen ◽  
Stephen P. Reynolds ◽  
Victoria M. Kaspi ◽  
Fiona A. Harrison ◽  
...  

2003 ◽  
Vol 594 (2) ◽  
pp. 732-740 ◽  
Author(s):  
Ping‐Hung Kuo ◽  
Chorng‐Yuan Hwang ◽  
Wing‐Huen Ip

1990 ◽  
Vol 142 ◽  
pp. 438-438
Author(s):  
B. Lokanadham

A study of the simultaneous observations of solar flares in optical, radio and X-ray bands is important in understanding the process of energy release and particle acceleration in the explosive phenomena of solar flares. In order to determine the characteristics of such energetic electrons in solar flares, a total number of 50 two-ribbon flares have been carefully selected during the period 1979-89 having simultaneous observational data in the optical, X-ray and radio bands.


1975 ◽  
Vol 68 ◽  
pp. 283-297 ◽  
Author(s):  
L. D. De Feiter

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.


2009 ◽  
Author(s):  
Jacco Vink ◽  
Jéro^me Rodriguez ◽  
Phillippe Ferrando

In this brief talk I should like to present a summary of some recent results on the mechanism of X -ray production in extars, with special emphasis on Sco X-1. These results are an outcome of a close collaboration between Professor S. Olbert of M.I.T. and me. As mentioned by Professor Burbidge earlier today, we hypothesize that galactic X-ray sources are in fact entities wherein ‘frozen in’, compressed magnetic field rapidly relaxes by transferring magnetic field energy to ultrarelativistic (u.r.) electrons. Consider a volume of space filled with magnetoactive plasma. For reasons elaborated on elsewhere (Manley & Olbert 1968, 1969) we do not expect the ionized gas to be homogeneous. Rather we expect it to consist of an aggregate of long thin plasmoids acting almost independently of one another. We now postulate the presence of random Alfvén waves (m.h.d. noise) propagating back and forth, along the plasmoids, and inquire into the possibility of charged particle acceleration by interaction with these noisy plasmoids. This is akin to the cosmic ray acceleration mechanism proposed by Fermi, who however, considered only interactions with large, approximately spherical plasmoids.


2018 ◽  
Vol 853 (1) ◽  
pp. 46 ◽  
Author(s):  
Toshiki Sato ◽  
Satoru Katsuda ◽  
Mikio Morii ◽  
Aya Bamba ◽  
John P. Hughes ◽  
...  

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