DISCOVERY OF γ-RAY PULSATION AND X-RAY EMISSION FROM THE BLACK WIDOW PULSAR PSR J2051–0827

Abstract

We report the discovery of pulsed γ-ray emission and X-ray emission from the black widow millisecond pulsar PSRJ2051-0827 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 on the Chandra X-Ray Observatory. Using threeyears of LAT data, PSRJ2051-0827 is clearly detected in γ-rays with a significance of 8σ in the 0.2-20GeV band. The 200MeV-20GeV γ-ray spectrum of PSRJ2051-0827 can be modeled by a simple power law with a photon index of 2.46 0.15. Significant (5σ) γ-ray pulsations at the radio period were detected. PSRJ2051-0827 was also detected in soft (0.3-7keV) X-ray with Chandra. By comparing the observed γ-rays and X-rays with theoretical models, we suggest that the γ-ray emission is from the outer gap while the X-rays can be from intra-binary shock and pulsar magnetospheric synchrotron emissions. © 2012. The American Astronomical Society. All rights reserved..