All-Moscow Seminar of Astrophysicists
(ASA)

Data on interstellar diffraction and refraction scintillation of pulsars are analyzed. The comparison between the theory and the observational data shows that two types of spectra for electron density fluctuations are realized in the interstellar medium: pure power law and piecewise with a break. The distribution of turbulent plasma in the Galaxy has a three component structure. Component A is diffuse and it is distributed outside of the spiral arms of the Galaxy. Component BI is cloudy and associated with Galactic arms. Component BII is extremely nonuniform and associated with HII regions and supernova remnants. The origin of the interstellar plasma turbulence is considered. The possible sources of turbulent energy are discussed.

The contribution of supernova bursts in the interstellar gas ionization and generation of turbulence are analyzed among other factors. A dependence of the emission measure EM observed in the directions of supernova remnants and pulsars on their ages is derived. The dependence have a well defined low boundary EM_min, which increases, when age is decreased. The EM_min does not reach a constant or maximum up to t ~ 500 years. Based on these results the conclusion is drawn, that the bulk of the radiant energy, that ionizes and heats the interstellar gas is released on early stage of supernova remnant evolution. It is supposed , that transform of bulk of the kinetic energy of supernova shell in to the thermal energy and emission of this energy occurs on supernova remnant age t < 100 years, when expanding supernova shell with enormous velocity (about 104 km/s) will be overtake the shell created by the presupernova, when the star was in supergiant stage. The estimations of values are the next: ionization energy of HII region around supernova (the supernova Stromgren sphere) E ~ 10⁵¹ erg, Stromgren sphere diameter L ~ 60 pc, electron concentration N_e ~ 7 cm^-3. The dependence of pulsar pulse broadening tau on pulsar age t have a clearly defined low boundary tau_min also. The tau_min depends on t as tau_min ~ t^-2, when t > 1000 years after supernova burst. The conclusion is made, that turbulence plays an important part in the origin and evolution of type II supernova Stromgren sphere.