A multi-frequency identification study of the SMC X-ray binary AX J0049-732

We present a high-resolution multi-frequency identification study of the Small Magellanic Cloud (SMC) region around the newly discovered X-ray pulsar AX J0049-732. ROSAT PSPC images show three X-ray sources near the ASCA source position. We combine X-ray, radio-continuum and optical data to identify these sources. RX J0049.2-7311 and RX J0049.5-7310 did not show long-term time variability nor pulsations during the ROSAT observations and both are not detected in the radio. We identify RX J0049.5-7310 with an emission line star in the catalogue of Meyssonier & Azzopardi (1993). This catalogue contains several known Be/X-ray binaries strongly suggesting the ROSAT source as new Be/Xray binary. RX J0049.5-7310 is therefore very likely the counterpart of the ASCA X-ray pulsar AX J0049-732. The third source RX J0049.1-7314 is associated with the supernova remnant (SNR) DEM S49 (B0047-735).