Parkes observations for project P1057 semester 2020APRS_01

In this proposal we request observations from the Parkes radio telescope to research bright periodic non-drift amplitude modulation pulsars. In these pulsar, the central and trailing components of the pulse profiles switch between a strong mode and a weak mode periodically. We plan to use the new Parkes Ultra-Wideband-Low receiver that will provide us with information at widely separated frequency bands. The mode switch pattern in a wide frequency range will be obtained and can confirm whether this effect is dependent on observation frequency. We will also obtain the polarisation profiles of the two states over wide-band. The observations will be used to investigate whether this phenomenon is associated with the presence of a core component in the pulse profile. Finally, we will compare them with periodical nulling pulsars and try to find some possible connection between them.