  We present detailed spectral and temporal characteristics over the whole
X-ray band. For this purpose data have been used from INTEGRAL, RXTE and
XMM-Newton. The INTEGRAL hard X-ray (>10 keV) time-averaged total spectrum, can
be described by a power law with a photon index Gamma = 1.13 +/- 0.06 and
extends to ~175 keV. No evidence for a spectral break is found. No significant
long-term time variability has been detected above 20 keV. Pulsed emission is
measured up to 270 keV (12.3 sigma; 20-270 keV). Three different pulse
components can be recognized in the pulse profiles: 1) a hard pulse which
contributes above ~4 keV, 2) a softer pulse not contributing in the hard X-ray
domain and 3) a very soft pulse component below 2 keV. Detailed phase-resolved
spectroscopy of the pulsed emission confirms long-term stability. The spectral
shape gradually changes with phase from a soft single power law to a complex
multi-component shape and then to a hard single power law. The spectrum
switches from a very hard (Gamma = 0.99 +/- 0.05) to a very soft (Gamma = 3.58
+/- 0.34) single power-law shape within a 0.1-wide phase interval. We identify
three independent components. The three shapes are a soft power law, a hard
power law and a curved shape. The phase distributions of the normalizations of
these spectral components form three decoupled pulse profiles. The soft
component peaks around phase 0.4 while the other two components peak around
phase 0.8. The width of the curved component (~0.25 in phase) is about half the
width of the hard component.
