Energy Spectra and Pulse Shapes of Pulsars at Metre Wavelengths

Abstract

Flux densities, pulse energy densities and mean pulse shapes of pulsars have been measured at frequencies of 61 and 102·5 MHz. In general, with increasing wavelength, the mean pulse width becomes larger and its profile becomes less complex. Instantaneous spectra obtained by simultaneous measurements show marked variability, but the mean spectrum is a stable characteristic of each pulsar. A common feature of pulsar mean spectra is a low frequency cutoff below about 100 MHz. The nature of this cutoff is discussed.