Tackling Radio Polarization of Energetic Pulsars

TL;DR

This paper enhances the rotating vector model for pulsar polarization by incorporating finite altitude effects and other phenomena, enabling better modeling of polarization sweeps in energetic pulsars and improving understanding of their emission geometry.

Contribution

It introduces a modified RVM including altitude effects, mode jumps, and scattering, providing a more accurate geometrical model for pulsar polarization.

Findings

Successfully fits polarization data for six Fermi-detected pulsars.

Demonstrates improved modeling of polarization sweeps over traditional RVM.

Provides insights into pulsar emission geometry through enhanced modeling.

Abstract

The traditional, geometrical rotating vector model (RVM) has proved particularly poor at capturing the polarization sweeps of the young energetic and millisecond pulsars detected by \textit{Fermi}. We augment this model by including finite altitude effects using a swept back vacuum dipole geometry. By further including the effects of orthogonal mode jumps, multiple emission altitudes, open zone growth via y-point lowering, and interstellar scattering, we show that a wide range of departures from RVM can be modeled well while retaining a geometrical picture. We illustrate these effects by fitting six \textit{Fermi}-detected pulsars (J0023$+$0923, J1024$-$0719, J1744$-$1134, J1057$-$5226, J1420$-$6048, and J2124$-$3358) and we describe how such modeling can improve our understanding of their emission geometry.