Pulsar interpulses and other off-pulse emission

It is stated that the pulse emission from pulsars is usually confined to a window having a width of a few per cent of the pulsar period. Seven of the 149 known pulsars, however, show secondary pulses, known as interpulses, that follow the relatively stronger main pulses by about half of the pulsar period. Whilst is seems that only a few pulsars have observable interpulses, not all of the known pulsars have been carefully examined for this. The results are here reported of an interpulse search conducted on the pulsars visible from Jodrell Bank. One new interpulse was discovered. The observations also revealed the presence of weak emission from regions other than the main pulse and interpulse windows in the case of three pulsars. The search took place between Jul 1975 and April 1976. Observations were made on approximately 100 pulsars at 327, 408 and 610 MHz and on about 50 of these pulsars at 151 and 240 MHz. The full period was observed for each pulsar for a total time of about 90 min. (U.K.)