Bubnov I. Broadband cosmic radio emission and its study at low frequencies

The research object: powerful cosmic radio sources in the frequency range 10 - 70 MHz. The purpose of the thesis: study of the properties of radio emission from powerful cosmic radio sources in a wide frequency band using the new generation active phased array. Methods: the experimental method of astronomic observations using the constructed broadband phased array and radio telescope UTR-2; the statistical processing methods of researches to analyze the observational data. Practical significance, scientific novelty: commissioned broadband high linear active dipole for low-frequency radio astronomy, the design of which received a patent, and built a 25-element broadband phased active array. It was the first time when a sporadic solar radio observations carried out in a continuous frequency band from 15 to 66 MHz, in which was registered sunny U-plash at the fundamental frequency (25 MHz) and the second (50 MHz) harmonic of the plasma frequency. It was the first time when the intersection point of the spectra of the supernova remnant Cassiopeia A and Cygnus A determined experimentally as a basis for monitoring changes the flux of Cassiopeia A in comparison with the flux of Cygnus A. Average value of the speed the secular decrease of the radio emission flux of Cassiopeia A was confirmed at a frequency of 38 MHz at 0.84% per year. Areas of application: astrophysics, radio astronomy, astronomy.