Modeling observed x-ray pulsar profiles.

摘要

The purpose of this work was to generalize pulse shape modeling to include the effect of light bending due to general relativity. A simple analytical formula was found to accurately describe the light bending effect, and was incorporated into the emission model for calculation of the pulse shapes from rotating accreting neutron stars. Least square fittings were performed to a subset of pulsars studied by Leahy, 1991{dollar}sp{lcub}lbrack2rbrack {rcub}.{dollar} The fittings with light bending showed significant improvement over the fittings without light bending, and the resulting derived emission region geometry gave narrower rings, as expected on theoretical grounds. The model was also applied to the luminosity dependent pulse profile of EXO2030+375. The relation between the luminosity and the properties of the emissions rings were studied. The lack of success of the model on EXO2030+375 was probably caused by the model being too simple geometrically. Future improvements to the model were discussed.