MEASUREMENTS OF RADIO-EMISSION FROM THE COMPACT SOURCE IN THE CRAB-NEBULA WITH THE URAN-1 INTERFEROMETER AT 16.7, 20 AND 25 MHZ

This paper presents the results of measurements of the Crab nebula in the decametre range with an interferometer whose baseline is 2.4-3.5×103 of the wavelength. Visibility function values, which in these observations determine the contribution by the compact source to the total nebula flux, have been measured at frequencies 16.7, 20 and 25 MHz to be 0.64±0.07, 0.43±0.04 and 0.31±0.03, respectively. The spectral index of the spectrum obtained for the compact source in the range 16.7-122 MHz is 2.09±0.04. Flattening of the nebula spectrum without the compact source has been confirmed for the decametre range. © 1979 D. Reidel Publishing Co.