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We propose a novel beam model for radio pulsars based on the scenario that the broadband and coherent emission from secondary relativistic particles, as they move along a flux tube in a dipolar magnetic field, forms a radially extended sub-beam with unique properties. The whole radio beam may consist of several sub-beams, forming a fan-shaped pattern. When only one or a few flux tubes are active, the fan beam becomes very patchy. This model differs essentially from the conal beam models in the respects of beam structure and predictions on the relationship between pulse width and impact angle $beta$ (the angle between line of sight and magnetic pole) and the relationship between emission intensity and beam angular radius. The evidence for this model comes from the observed patchy beams of precessional binary pulsars and three statistical relationships found for a sample of 64 pulsars, of which $beta$ were mostly constrained by fitting polarization position angle data with the Rotation Vector Model. With appropriate assumptions, the fan beam model can reproduce the relationship between 10% peak pulse width and $|beta|$, the anticorrelation between the emission intensity and $|beta|$, and the upper boundary line in the scatter plot of $|beta|$ versus pulsar distance. An extremely patchy beam model with the assumption of narrowband emission from one or a few flux tubes is studied and found unlikely to be a general model. The implications of the fan beam model to the studies on radio and gamma-ray pulsar populations and radio polarization are discussed.
In the canonical picture of pulsars, radio emission arises from a narrow cone centered on the stars magnetic axis but many basic details remain unclear. We use high-quality polarization data taken with the Parkes radio telescope to constrain the geom
It is usually thought that a single equation of state (EoS) model correctly represents cores of all compact stars. Here we emphasize that two families of compact stars, viz., neutron stars and strange stars, can coexist in nature, and that neutron st
The X-ray radiation produced on the surface of accreting magnetised neutron stars is expected to be strongly polarised. A swing of the polarisation vector with the pulsar phase gives a direct measure of the source inclination and magnetic obliquity.
The Parkes telescope has been monitoring 286 radio pulsars approximately monthly since 2007 at an observing frequency of 1.4 GHz. The wide dispersion measure (DM) range of the pulsar sample and the uniformity of the observing procedure make the data-
Neutron stars spin down over time due to a number of energy-loss processes. We provide tantalizing population-based evidence that millisecond pulsars (MSPs) have a minimum ellipticity of $epsilonapprox10^{-9}$ around their spin axis and that, consequ