Gamma-ray and Radio Properties of Six Pulsars Detected by the Fermi Large Area Telescope

TL;DR

This paper reports the detection and analysis of gamma-ray and radio properties of six diverse pulsars observed by the Fermi LAT, highlighting their light curve shapes, emission models, and polarization characteristics.

Contribution

It provides new gamma-ray detections for six pulsars and compares their light curves and polarization data with high-altitude emission models.

Findings

Most pulsars have single-peaked gamma-ray light curves.

Some pulsars show hints of double-peaked structures.

Gamma-ray emission phases generally match high-altitude models.

Abstract

We report the detection of pulsed gamma-rays for PSRs J0631+1036, J0659+1414, J0742-2822, J1420-6048, J1509-5850 and J1718-3825 using the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (formerly known as GLAST). Although these six pulsars are diverse in terms of their spin parameters, they share an important feature: their gamma-ray light curves are (at least given the current count statistics) single peaked. For two pulsars there are hints for a double-peaked structure in the light curves. The shapes of the observed light curves of this group of pulsars are discussed in the light of models for which the emission originates from high up in the magnetosphere. The observed phases of the gamma-ray light curves are, in general, consistent with those predicted by high-altitude models, although we speculate that the gamma-ray emission of PSR J0659+1414, possibly featuring the softest spectrum of all Fermi pulsars coupled with a very low efficiency, arises from relatively low down in the magnetosphere. High-quality radio polarization data are available showing that all but one have a high degree of linear polarization. This allows us to place some constraints on the viewing geometry and aids the comparison of the gamma-ray light curves with high-energy beam models.