The dynamics and structure of plasma inhomogeneities in the Crab Nebula

The results of studies of the dynamics and structure of plasma inhomogeneities in the Crab Nebula carried out during 2002–2015 at 111 MHz on the Large Phased Array of the Pushchino Radio Astronomy Observatory are presented. Giant pulses of the pulsar PSR B0531+21 were observed and analyzed using specialized software designed to enable characterization of the scattering of a pulse via modeling of its passage through the scattering medium. The results of this analysis for the scattering of giant pulses are compared to variations in the dispersion measure, derived using data from Jodrell Bank Observatory (United Kingdom). Numerous non-stationary events associated with enhanced scattering are identified during the indicated period. The strongest scattering was observed during 2012–2014. The corresponding data are interpreted as eclipses of the pulsar by filaments in the Crab Nebula. A correlation between the variations in the scattering and dispersion measure is observed.