A BEPPOSAX OBSERVATION OF XTE J0055-724 = 1SAX J0054.9-7226, A NEW X-RAY PULSAR IN THE SMC

We report on the result of a BeppoSAX Target of Opportunity Observatio n of the hard pulsating X-ray source XTE J0055-724 = 1SAX J0054.9-7226 , in the Small Magellanic Cloud (SMC). The source was detected by Bepp oSAX at a flux level of similar to 2.10(-11) erg cm(-2) s(-1) (2-10 ke V) and its position is consistent with that of the ROSAT PSPC source 1 WGA J0054.9-7226 and the Einstein source 2E 0053.2-7242. Both these so urces were known to possess a marked variability, on timescales rangin g from months to years. The BeppoSAX energy spectrum of 1SAX J0054.0-7 226 is hard and well modelled by an absorbed hard power-law model with a photon index similar to 0.81. BeppoSAX detected up to 40 keV the si milar to 59 s pulsations originally discovered with by RXTE (Marshall & Lochner 1998a; Santangelo et al. 1998).