Broadband observations of the new X-ray burster sax J1747.0-2853 during the 1998 March outburst

We report on our discovery and follow-up observations of the X-ray source S AX J1747.0-2853 detected in outburst on 1998 March 10 with the BeppoSAX Wid e-Field Cameras in the energy range 2-28 keV. The source is located about 0 .degrees5 off the Galactic nucleus. A total of 14 type I X-ray bursts were detected in spring of 1998, thus identifying the object as a likely low-mas s X-ray binary harboring a weakly magnetized neutron star. Evidence for pho tospheric radius expansion is present in at least one of the observed burst s, leading to an estimate of the source distance of similar to9 kpc. We per formed a follow-up target of opportunity observation with the BeppoSAX narr ow-field instruments an March 23 for a total elapsed time of 7.2 x 10(4). T he source persistent luminosity was 2.6 x 10(36) ergs s(-2) in the 2-10 keV energy range. The broadband spectral data (1-200 keV) are consistent with a remarkable hard X-ray spectrum detected up to similar to 150 keV, highly absorbed at low energies (N-H similar or equal to 10(23) cm(-2)) and with c lear evidence for an absorption edge at similar to7 keV. A soft thermal com ponent is also observed, which can be described by single-temperature black body emission at similar to0.6 keV.