X-Ray timing, spectroscopy, and photometry of the anomalous X-ray pulsar candidate CXOU J010043.1-721134

We present new X-ray timing and spectral results on the 8.0 s X-ray pulsar CXOU J010043.1-721134 from a series of observations using the Chandra X-Ray Observatory. We found a spin period in 2004 January of 8.020392-0.000009 s. A comparison of this to the 2001 Chandra observations implies a period derivative P = (1.88 +/- 0.08) x 10(-11) s s(-1), leading to an inferred dipole surface magnetic field of 3.9 x 10(14) G. The spectrum is well fit to an absorbed blackbody of temperature kT = 0.38 +/- 0.02 keV with a power-law tail of photon index Gamma = 2.0 +/- 0.6. We find that the source has an unabsorbed X-ray flux (0.5-10 keV) of 4(-1)(+2) x 10(-13) ergs cm(-2) s(-1) and a corresponding X-ray luminosity of similar to 2 x 10(35) ergs s(-1) for a distance of 60 kpc. These properties support the classification of CXOU J010043.1-721134 as the seventh confirmed anomalous X-ray pulsar, the eleventh confirmed magnetar, and the first magnetar to be identified in the Small Magellanic Cloud.