Polarisation of synchrotron radiation from isolated neutron stars

Abstract

Pulsars are enigmatic neutron stars which have defied efforts to understand them for over 40 years. POREC (Pulsar Optical Reverse Engineering Code) was first written to constrain pulsar emission theories through constraining the emission location. POREC originally used the Westfold, Legg and Gleeson (WLG) model to calculate the incoher- ent optical emission that would be seen. In this work it is shown that the WLG model fails for optical (and higher) wavelengths in high magnetic fields (> 10^6 G). A new model for incoherent synchrotron radiation in high magnetic fields (the DS model) is proposed. While this does solve the original problems associated with the WLG model, the DS model has its own weaknesses. A full discussion of the derivation of the DS model and of the various weaknesses of the DS model will be covered. POREC is updated to the DS model. A new pitch angle distribution (PAD) for POREC is proposed, and the problems with this new PAD discussed. The new simulations are compared against the latest observations of the Crab nebula. While these new simulations give a better fit to the observations than previous models using the WLG model, there are still several serious problems with the results from POREC. These problems will also be covered in more detail.