Pulsed Hard X-Ray Spectrum of PSR B1509-58.

摘要

OSSE observed the 150 ms X-ray pulsar PSR B1509-58 in the supernova remnant MSH 15-52 for four weeks in 1992. The pulsed spectrum from 50 keV to 5 MeV is well-fit by a single power law photon spectrum of the form (3.14 plus or minus 0.16) x 10(exp 6) x(E/118.5 keV)(exp-1.68 plus or minus 0.09) photons cm(exp-2) s(exp-1) keV(exp -1). this is significantly harder than the Crab pulsar spectrum in this energy range. The Ginga soft X-ray spectrum (2-60 keV) reported by Kawai et al. Is significantly harder than the observed OSSE spectrum and predicts a flux two times higher than we observe in the approximately 55 -170 keV energy band. This requires a break to a steeper spectrum somewhere in the intermediate energy range (approximately 40 - 80 keV). The spectrum must soften again at higher energies or the pulsar would have easily been detected by EGRET, COS B, and SAS-2.