The two - component X -

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 radio counterparts, and exhibit long-term increases in pulse period. The phase-averaged 0.5–10 keV spectrum can be described by an absorbed powerlaw 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 blackbody emission from this source strengthens the similarity with two of the more well studied “anomalous” pulsars, 1E 2259+586 and 4U 0142+614. 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 continues to spin-down, but at a slower rate than obtained from the previous measurements in 1994 and 1996.