A heliospheric density model and type III radio bursts

A heliospheric density model is derived by evaluating the spherical solutions of magnetohydrostatic equations including the thermal pressure and the gravitational force of the Sun. The model resulting as a special solution of Parker's wind equation covers a range from the low corona up to 5 AU and, surprisingly, agrees very well with observations. Such a model is required for the interpretation of solar and interplanetary radio observations since the emission of the radio radiation is regarded to be generated near the local electron plasma frequency, which depends on the electron number density. Thus, the density model yields the radial distance of the radio source from the Sun and, consequently, the radial source velocity from the drift in dynamic radio spectra. The model is applied for estimating the velocity of electron beams generating solar and interplanetary type III radio bursts. (orig.)SIGLEAvailable from TIB Hannover: RR 7310(99-11) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Catalogue of solar type II radio bursts observed from September 1990 to December 1993 and their statistical analysis

Solar type II radio bursts represent the radio signature of shock waves travelling through the solar corona. They are associated with flares, coronal mass ejections (CME's) and interplanetary shocks. Type II radio bursts appear as emission stripes slowly drifting from high to low frequencies in dynamic radio spectra. The spectral features of all solar type II radio bursts observed by the new radiospectrograph of the Astrophysikalisches Institut Potsdam in Tremsdorf during the time period from September 1, 1990 to December 31, 1993, i.e., during the first part of the ULYSSES spacecraft mission, are summarized and statistically investigated. (orig.)Available from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman