Ja n 20 04 Spectrum of Solar Type I Continuum Noise Storm in the 50 - 80 MHz band , and Plasma characteristics in the associated source region

Continuum observations of a solar noise storm in the frequency range of 50 80 MHz observed with the Gauribidanur radio spectrograph during 2000 September, 26 & 27, are presented here. The radio spectral index of the noise storm continuum in the band 50 80 MHz is found to be ≈ 3.65 during the above period. The Noise Storm continuum radiation is explained as a consequence of the non-thermal, plasma emission mechanism. The beam-density of suprathermal electrons is estimated for the coronal plasma near the source region of storm radiation. Supplementary evidence for the density-estimate is provided by way of analysing the imaging data from the SXT on-board the Yohkoh spacecraft, and the LASCO, MDI, and EIT on board the SoHO spacecraft. Subject headings: Sun: radio radiation — radiation mechanisms: non-thermal — plasmas Joint Astronomy Programme, Department of Physics, Indian Institute of Science, Bangalore 560012, Karnataka, INDIA Indian Institute of Astrophysics, Koramangala, Bangalore 560034, Karnataka, INDIA