1998A&A...334..925O

The 6.4s 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 5-11s, show no evidence of optical or radio counterparts, and exhibit long-term increases in pulse period. The phase-averaged 0.5-10keV spectrum can be described by an absorbed power-law and blackbody model. The best-fit photon index is 2.5±0.2 and the blackbody temperature and radius are 0.64±0.01keV and 0.59±0.02km (for a distance of 3kpc), 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±0.00001s 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.