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DUAL FREQUENCY VARIABILITY STUDY OF AN ACTIVE REGION

DSpace at IIT Bombay

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Field Value
 
Title DUAL FREQUENCY VARIABILITY STUDY OF AN ACTIVE REGION
 
Creator SHEVGAONKAR, RK
KUNDU, MR
 
Subject solar
 
Description A short-time variability study of a solar active region simultaneously at 6 and 2 cm wavelengths was carried out using the VLA. The observations show interesting uncorrelated brightness temperature variations at the two wavelengths. The observed low brightness temperatures indicate that the emission is mainly originating from the chromosphere - corona transition region. A transition region model with constant pressure and power-law temperature variation as a function of height has been assumed to analyse the data. The uncorrelated variation of the observed brightness temperature at the two wavelengths suggest different dominant emission mechanisms (bremsstahlung at 2cm and gyro-resonance at 6 cm) operative at the two wavelengths. It is shown that an independent variation of a few percent in the magnetic field (900 +/-45 G) and a factor of two variation in the density (2 to 4 x 10(10) cm-3) over a time scale of few hours is required to explain the uncorrelated brightness temperature variations at the two wavelengths.
 
Publisher KLUWER ACADEMIC PUBL
 
Date 2011-08-17T04:41:09Z
2011-12-26T12:55:21Z
2011-12-27T05:44:09Z
2011-08-17T04:41:09Z
2011-12-26T12:55:21Z
2011-12-27T05:44:09Z
1990
 
Type Article
 
Identifier IAU SYMPOSIA, (142), 489-493
0074-1809
http://dspace.library.iitb.ac.in/xmlui/handle/10054/9748
http://hdl.handle.net/10054/9748
 
Language en