Systematic Rossi X-Ray Timing Explorer ( RXTE ) observations of the Small Magellanic Cloud ( SMC ) have revealed a previously unknown transient X-ray pulsar with a pulse period of 95s .
The 95s pulsar , provisionally designated XTE SMC95 , was detected in three Proportional Counter Array ( PCA ) observations during an outburst spanning 4 weeks in March/April 1999 .
The pulse profile is double peaked reaching a pulse fraction of \approx 0.8 .
The X-ray spectrum is well represented by an absorbed power-law with a photon index of 1.4 and mean unabsorbed flux of \ga 8.95 \times 10 ^ { -11 } ergs cm ^ { -2 } s ^ { -1 } ( 3 - 25 keV ) .
The source is proposed as a Be/neutron star system on the basis of its pulsations , transient nature and characteristically hard X-ray spectrum .
The 2-10 keV X-ray luminosity implied by our observations is \ga 2 \times 10 ^ { 37 } ergs s ^ { -1 } which is consistent with that of normal outbursts seen in Galactic systems .
This discovery adds to the emerging picture of the SMC as containing an extremely dense population of transient high mass X-ray binaries .