Ginga observations of isolated pulsars: PSR 1509-58 and the Crab pulsar.

The energy spectra and the pulse light curve of PSR1509-58 in the X-ray range 2-60 keV are presented. The X-ray pulse spectrum can be fitted by a power-law model with a photon index of ∼1.3. The non-pulse component is softer, and has a photon index of 2.2 if modeled by a power-law. The Crab pulsar was observed by Ginga in March 1987 and September 1991. The variation of single pulse intensity was evaluated with a best statistics in the 2-11 keV X-ray, but no significant deviation from the Poisson fluctuation was found. The long-term variation of the relative intensity of the two peaks in the pulse profile was studied using the data taken 4.5 years apart. Unlike in the gamma-ray range, no significant variation of the pulse peaks were found. In this respect the soft X-ray pulse in the Crab pulsar shares more characteristics in common with the optical pulserather than the gamma-ray.