THE 2-COMPONENT X-RAY-SPECTRUM OF THE 6.4-S PULSAR 1E-1048.1-5937

The 6.4 s X-ray pulsar 1E 1048.1-5937 was observed by BeppoSAX in 1997 May. This source belongs to the class of ''anomalous'' pulsars which have pulse periods in range 5-11 s, show no evidence of optical or rad io counterparts, and exhibit long-term increases in pulse period. The phase-averaged 0.5-10 keV spectrum can be described by an absorbed pow er-law and blackbody model. The best-fit photon index is 2.5+/-0.2 and the blackbody temperature and radius are 0.64+/-0.01 keV and 0.59+/-0 .02 km (for a distance of 3 kpc), respectively. The detection of black body emission from this source strengthens the similarity with two of the more well studied ''anomalous'' pulsars, 1E 2259+586 and 4U 0142+6 14. There is no evidence for any phase dependent spectral changes. The pulse period of 6.45026+/-0.00001 s implies that 1E 1048.1-5937 conti nues to spin-down, but at a slower rate than obtained from the previou s measurements in 1994 and 1996.