Discovery of {\gamma}-ray pulsation and X-ray emission from the black widow pulsar PSR J2051-0827

TL;DR

This paper reports the discovery of gamma-ray pulsations and X-ray emissions from the black widow pulsar PSR J2051-0827, providing insights into its high-energy emission mechanisms using Fermi and Chandra data.

Contribution

First detection of gamma-ray pulsations and X-ray emission from PSR J2051-0827, with spectral analysis and emission origin modeling.

Findings

Gamma-ray emission detected with 8σ significance in 0.2-20 GeV band.

X-ray emission detected in 0.3-7 keV band.

Gamma-ray spectrum modeled by a power-law with photon index 2.46.

Abstract

We report the discovery of pulsed {\gamma}-ray emission and X-ray emission from the black widow millisecond pulsar PSR J2051-0827 by using the data from the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope and the Advanced CCD Imaging Spectrometer array (ACIS-S) on the Chandra X-ray Observatory. Using 3 years of LAT data, PSR J2051-0827 is clearly detected in {\gamma}-ray with a signicance of \sim 8{\sigma} in the 0.2 - 20 GeV band. The 200 MeV - 20 GeV {\gamma}-ray spectrum of PSR J2051-0827 can be modeled by a simple power- law with a photon index of 2.46 \pm 0.15. Significant (\sim 5{\sigma}) {\gamma}-ray pulsations at the radio period were detected. PSR J2051-0827 was also detected in soft (0.3-7 keV) X-ray with Chandra. By comparing the observed {\gamma}-rays and X-rays with theoretical models, we suggest that the {\gamma}-ray emission is from the outer gap while the X-rays can be from intra-binary shock and pulsar magnetospheric synchrotron emissions.