The two-component X-ray spectrum of the 6.4 s pulsar 1E 1048.1-5937
T. Oosterbroek 1,
A.N. Parmar 1,
S. Mereghetti 2 and
G.L. Israel 3
Received 31 October 1997 / Accepted 6 March 1998
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 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 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.
Key words: stars: neutron pulsars: individual (1E 1048.1 5937) X-rays: stars
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© European Southern Observatory (ESO) 1998
Online publication: June 2, 1998