INTEGRAL observations of the Crab pulsar
INAF IASF-Pa, via U. La Malfa 153, 90146 Palermo, Italy e-mail: email@example.com
2 INAF IASF-Bo, via P. Gobetti 101, 40129 Bologna, Italy
Accepted: 5 January 2006
Aims.The paper presents the timing and spectral analysis of several observations of the Crab pulsar performed with INTEGRAL in the energy range 3–500 keV.
Methods.All these observations, when summed together provide a high statistics data set which can be used for accurate phase resolved spectroscopy. A detailed study of the pulsed emission at different phase intervals is performed.
Results.The spectral distribution changes with phase showing a characteristic reverse S shape of the photon index. Moreover the spectrum softens with energy, in each phase interval, and this behavior is adequately modeled over the whole energy range 3–500 keV with a single curved law with a slope variable with Log(E), confirming the BeppoSAX results on the curvature of the pulsed emission. The bending parameter of the log-parabolic model is compatible with a single value of over all phase intervals.
Conclusions.Results are discussed within the three-dimensional outer gap model.
© ESO, 2006