Faraday Dispersion in the Solar Atmosphere.

Abstract

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Faraday Dispersion in the Solar Atmosphere. Akabane, K. ; Cohen, M. H. Abstract The degree of linear polarization in solar bursts was measured simultaneously at two bandwidths, 10 and 22 Kc, each having the same center frequency, 201.6 Mc. A number of partially linearly polarixed type III bursts were seen, and in every case the burst was more polarized in the narrow band than in the wide band. According to the theory of Faraday dispersion, the ratio between the degrees of polarization observed at two bandwidths gives the degree of polarization at the source Po, the Faraday rotation angle ~, and the dispersion angle 0. A typical example is as follows: Po~0.2 ~~5X103 rad, corresponding to fNHdz~S.5X1015 (cm, gauss); 0 1 rad for 10-Kc bandwidth. From 37 linearly polarized bursts the following interpretations are tentatively suggested: (1)The intensity of the general magnetic field of the sun can be estimated to be less than 1 gauss at the pole, assuming that the source of the general magnetic field produces a bipolar field in the equatorial region, as well as in the polar region. (2) In some cases there is a weak magnetic field (~t gauss) near the source of a burst (for the assumed electron density); if a strong magnetic field exists there, it might be disordered so as to diminish the total amount of Faraday rotation. (3) The number of observed bursts increases steeply with decreasing Po In the discussion of Faraday dispersion the band shape of the receiver is approximated by a Gaussian function. This results in single-valued determinations of Po, 4), and 0. Publication: The Astronomical Journal Pub Date: 1960 DOI: 10.1086/108095 Bibcode: 1960AJ.....65R..49A full text sources ADS |