Pulsar spectra of radio emission

The database of Lorimer et al. (1995, Cat. <J/MNRAS/273/411>) has been extended to frequencies higher than 1.4GHz and lower than 300MHz. Our results show that above 100 MHz the spectra of the majority of pulsars can be described by a simple power law with average value of spectral index <{alpha}>=-1.8+/-0.2.

A rigorous analysis of spectral fitting revealed only about 10% of spectra which can be modelled by the two power law. Thus, it seems that single power law is a rule and the two power law spectrum is a rather rare exception, of an unknown origin, to this rule. We have recognized a small number of pulsars with almost flat spectrum ({alpha}>=-1.0) in the wide frequency range (from 300MHz to 20GHz) as well as few pulsars with a turn-over at unusually high frequency (~1GHz).