DOI: https://doi.org/10.18524/1810-4215.2017.30.114670

MICROWAVE EMISSION OF SOLAR FLARES: CORONAL MASS EJECTIONS AND SHOCK WAVES

E. A. Isaeva, Yu. T. Tsap

Анотація


Coronal  mass  ejections  (CMEs)  mostly affect  the  geomagnetic  field.  These  structures  are  observed  and  studied  with  coronagraphic  images  thereforewe don’t see the corona in the plane of the sky and  the measurements  of  the  propagation  speed  for  solar  disk events  are  not  accessible  to  coronagraphic  observations. This suggests that microwave emission of solar flares that can  be  attributed  to  the  gyrosynchrotron  mechanism  of mildly relativistic electrons can be used. In turn, the relationship  between  coronal  shock  waves  and  CMEs  also remains unclear.      The data set that we use in this study is based on microwave (μ) observations of spectral fluxes Fμ  at 8.8 GHz obtained with the Radio Solar Telescope Network for the 124 proton solar events . The correlation coefficient r between the CME velocities VCME  and integral fluxes of microwave  emission    ∫Fμdt  achieves  of  about  0.8  while  it does not exceed 0.36 between VCME  and the  shock waveelocities.  It has been found the quite strong correlation between  the  growth  rate  of  microwave  emission  and  the deceleration  of  frequency  drift  in  the  frequency  range  of25-180 GHz (r ≈ 0.66).  The obtained results suggest that microwave observation can be used to predict  VCME  and the  shock  wave  generation  occurs  in  the  region  of  flare energy release. 


Ключові слова


Coronal mass ejections (CMEs); shock waves

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Посилання


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