X-ray observations of the Large Magellanic Cloud pulsar PSR B0540-69 and its pulsar wind nebula

Abstract

PSR B0540-69 is a young pulsar in the Large Magellanic Cloud that has similar properties with respect to the Crab Pulsar, and is embedded in a pulsar wind nebula (PWN). We have analysed the complete archival Rossi X-Ray Timing Explorer (RXTE) data set of observations of this source, together with new Swift/XRT (X-Ray Telescope) and International Gamma-Ray Astrophysics Laboratory (INTEGRAL)/IBIS (Imager on Board INTEGRAL Satellite) data. Accurate light curves are produced in various energy bands between 2 and 60 keV, showing no significant energy variations of the pulse shape. The spectral analysis shows that the pulsed spectrum is curved, and is best fitted up to 100 keV by a log-parabolic model: this strengthens the similarities with the Crab Pulsar, and is discussed in the light of a phenomenologic multicomponent model. The total emission from this source is studied, the relative contributions of the pulsar and the PWN emission are derived and discussed in the context of other INTEGRAL-detected pulsar/PWN systems.