On the Asymmetry of Pulsar Radio Emission from Both Poles

Wu, Xiancong

The radio emissions from pulsars are believed to originate from the polar cap regions of their dipolar magnetic fields. However， it is uncertain whether the radio radiation from both magnetic poles is similar. The observation of a precessing pulsar with interpulse emission， PSR J1906+0746， explicitly demonstrated dissimilar radiation beam patterns from both poles. To further examine the universality， we collected integrated profiles from 17 pulsars， of which 4 were from FAST， 8 from MeerKAT， and 5 from Parkes. These profiles exhibited interpulse emissions， and their polarisation position angle (PA) swings conformed to the rotating vector model (RVM). We compared the emission height， the radiation beam intensity， the magnetic azimuth width， and the radiation beam radius of both poles for each pulsar with their geometry， which was determined from RVM. As a result， a total of 11 pulsars can be observed from the same region of both magnetic poles. Out of these， only 1 pulsar showed similar emission heights from both poles， 5 pulsars exhibited similar beam intensity， 2 pulsars had similar beam radius， and none of the pulsars displayed similar azimuth widths. In conclusion， it is common for pulsar radio radiation to exhibit asymmetry from both poles， which necessitates further discussion.