Fermi Large Area Telescope Observations of Gamma-ray Pulsars PSR J1057-5226, J1709-4429, and J1952+3252

TL;DR

This paper reports Fermi LAT observations of three gamma-ray pulsars, analyzing their pulse profiles and spectra over 13 months, and measuring their cutoff energies to better understand their emission mechanisms.

Contribution

First measurement of cutoff energies for these pulsars, providing new insights into gamma-ray emission processes and spectral evolution with phase.

Findings

Confirmed pulsed emission from three pulsars

Measured spectral cutoff energies for the first time

Observed pulse profile evolution with energy

Abstract

The Fermi Large Area Telescope (LAT) data have confirmed the pulsed emission from all six high-confidence gamma-ray pulsars previously known from the EGRET observations. We report results obtained from the analysis of 13 months of LAT data for three of these pulsars (PSR J1057-5226, PSR J1709-4429, and PSR J1952+3252) each of which had some unique feature among the EGRET pulsars. The excellent sensitivity of LAT allows more detailed analysis of the evolution of the pulse profile with energy and also of the variation of the spectral shape with phase. We measure the cutoff energy of the pulsed emission from these pulsars for the first time and provide a more complete picture of the emission mechanism. The results confirm some, but not all, of the features seen in the EGRET data.