# The fan beam model for the pulse evolution of PSR J0737-3039B

## TL;DR

This paper investigates how a fan-beam model explains the evolving radio pulse profile of pulsar PSR J0737-3039B, showing it can account for observed profile changes due to geodetic precession.

## Contribution

The study demonstrates that the fan-beam geometry effectively models the pulse evolution, offering a viable alternative to traditional conal beam models.

## Key findings

- Fan-beam model reproduces pulse width evolution.
- Fan-beam geometry explains profile morphology changes.
- Supports fan-beam as a serious alternative to conal models.

## Abstract

Average radio pulse profile of a pulsar B in a double pulsar system PSR J0737-3039A/B exhibits an interesting behaviour. During the observation period between 2003 and 2009, the profile evolves from a single-peaked to a double-peaked form, following disappearance in 2008 indicating that the geodetic precession of the pulsar is a possible origin of such behaviour. The known pulsar beam models can be used to determine the geometry of PSR J0737-3039B in the context of the precession. We study how the fan-beam geometry performs in explaining the observed variations of the radio profile morphology. It is shown that the fan beam can successfully reproduce the observed evolution of the pulse width, and should be considered as a serious alternative for the conal-like models.