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VLA Observations of Angular Broadening Close to the Sun

Published online by Cambridge University Press:  12 April 2016

Pradeep Gothoskar ,
K.R. Anantharamahaia ,
Ketan Desai  and
A.P. Rao
Pradeep Gothoskar
Affiliation:
NCRA, TIFR, Pune, 411007, India
K.R. Anantharamahaia
Affiliation:
RRI, Bangalore, 560080, India
Ketan Desai
Affiliation:
NRAO, U.S.A.
A.P. Rao
Affiliation:
NCRA, TIFR, Pune, 411007, India

Abstract

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We present synthesis imaging of scatter-broadening of radio sources carried out using the Very Large Array (VLA) at six radio frequencies during the period of solar minimum. Three compact radio sources were observed from 2 to 16 solar radii around the sun. The data indicate highly anisotropic scattering. The scatter-broadening was estimated from the area of the scattered image and was found to be factor of two lower and orientation of magnetic fields was closer to the radial direction. Present observations confirm the variation of scatter-broadening with solar elongation.

Type
Chapter Four Extreme Scattering Events, Distribution of Material and IPS
Information
International Astronomical Union Colloquium , Volume 182: Sources and Scintillations: Refraction and Scattering in Radio Astronomy , 2001 , pp. 193 - 196
Copyright
Copyright © Kluwer 2001

References

Anantharamaiah, K.R., Gothoskar, P. and Cornwell, T.J.: 1994, Radio synthesis observations of scattering in the inner heliosphere, Astron. Astrophys. 15, 387.Google Scholar
Armstrong, J.W., Coles, W.A., Rickett, B.J and Kojima, K.: 1986, Solar wind observations near the sun, The sun and the Heliosphere in three dimensions, Proc. of the 19th ESLAB Symposium, Les Diablerets, 59–64.Google Scholar
Armstrong, J.W., Coles, W.A., Kojima, M. and Rickett, B.J.: 1990, Observations of field-aligned density fluctuations in the inner solar wind, Astrophys. J. 358, 685–692.Google Scholar
Narayan, R., Anantharamaiah, K.R. and Cornwell, T.J.: 1989, Refractive radio scintillation in the solar wind, Mon. Not. R. Astron. Soc. 241, 403–413.Google Scholar
Manoharan, P.K., Kojima, M. and Misawa, H.: 1994, The spectrum of electron density fluctuations in the solar wind and its variations with solar wind speed, Geophys. Res. 99, 23411–23420.Google Scholar
Yamauchi, Y., Misawa, H., Kojima, M., Mori, H., Tanaka, T., Takaba, H., Kondo, T., Tokumaru, M. and Manoharan, P.K.: 1995, Observations of micro-turbulence in the solar wind near the sun with interplanetary scintillation, Solar Wind-8, Conf. Proc., 82.Google Scholar