The two-component X-ray spectrum of the 6.4 s pulsar 1E 1048.1-5937

Abstract

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 power-law and blackbody model. The best-fit photon index is 2.5+/-0.2 and the blackbody temperature and radius are 0.64+/-0.01 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.