The X-ray Spectrum of the Plerionic System PSR B1509-58/MSH 15-52
D. Marsden, P. R. Blanco, D. E. Gruber, W. A. Heindl, M. R. Pelling, L. E. Peterson, R. E. Rothschild, A. H. Rots, K. Jahoda, D. J. Macomb
Abstract
We present the results of observations of the PSR B1509
−
58/MSH 15
−
52 system in X-rays (
2−250
keV) by the Rossi X-ray Timing Explorer. The spectra of the peak of the pulsed component (radio phase
0.17−0.53
) is fit by a power law of photon index
1.36±0.01
, with no evidence of a high energy spectral break seen up to
∼200
keV. For the off-pulse spectral component, the spectrum from
2−250
keV is fit by a power law of photon index
2.215±0.005
. An iron emission line at 6.7 keV with an equivalent width of 129 eV improves the fit, but only at a marginal significance. Thermal bremsstrahlung and Raymond-Smith models produce much worse fits to the unpulsed data. The lack of a high energy spectral break in the pulsed emission implies an efficiency of
≥3
in the conversion of pulsar spindown energy to pulsed X-rays in the system.