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Discovery of the Slowest X-Ray Pulsar in the SMC, AX J0049.5-7323, with ASCA

Jun Yokogawa·Kensuke Imanishi·Masaru Ueno·Katsuji Koyama
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Abstract

The discovery of coherent pulsations with ASCA from an X-ray source, AX J0049.5-7323, is reported. The barycentric period was determined to be 755.5 +/- 0.6 s, which is the longest among X-ray pulsators in the SMC. The X-ray spectrum has been found to be unchanged through ASCA observations, with a photon index of ~0.8 and a luminosity of ~5e35 erg s^-1 (0.7-10 keV). Archival data of the Einstein and the ROSAT satellites indicate that the flux has been < 1e-12 erg s^-1 cm^-2 (< 5e35 erg s^-1) for over 20 years and exhibits a variability with a factor of >10. We argue that AX J0049.5-7323 is an X-ray pulsar with a Be star companion.

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Jun Yokogawa, Kensuke Imanishi, Masaru Ueno, Katsuji Koyama. 2000-11-14. Discovery of the Slowest X-Ray Pulsar in the SMC, AX J0049.5-7323, with ASCA. https://doi.org/10.1093/pasj%2F52.6.l73

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