THE SPIN-DOWN RATE AND X-RAY FLUX OF 1E-1048.1-5937

We present the results of observations of the pulsating X-ray source 1 E 1048.1-5937 made with the ASCA GIS detectors. The source continues t o exhibit spin-down at the faster rate reported from ROSAT observation s rather than the slower spin-down rate initially measured. The X-ray spectrum can be satisfactorily fitted with a power-law model, and we c annot discriminate between this and the power law plus blackbody combi nation used for two Other members of this class. The mean flux is appr oximately a factor of 3 weaker than measured with EXOSAT, which is con sistent with X-ray emission being powered by accretion. While these re sults reinforce the similarity to 1E 2259+586, the pulsed fraction of 1E 1048.1-5937 is much larger with little energy dependence.