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ASCA Discovery of a Be X-Ray Pulsar in the SMC: AX J0051-733

Kensuke Imanishi·Jun Yokogawa·Masahiro Tsujimoto·Katsuji Koyama
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Abstract

ASCA observed the central region of the Small Magellanic Cloud, and found a hard X-ray source, AX J0051-733, at the position of the ROSAT source RX J0050.8-7316, which has an optical counterpart of a Be star. Coherent X-ray pulsations of 323.1 +/- 0.3 s were discovered from AX J0051-733. The pulse profile shows several sub-peaks in the soft (0.7-2.0 keV) X-ray band, but becomes nearly sinusoidal in the harder (2.0-7.0 keV) X-ray band. The X-ray spectrum was found to be hard, and is well fitted by a power-law model with a photon index of 1.0 +/- 0.4. The long-term flux history was examined with the archival data of Einstein observatory and ROSAT; a flux variability with a factor > 10 was found.

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Kensuke Imanishi, Jun Yokogawa, Masahiro Tsujimoto, Katsuji Koyama. 1999-10-27. ASCA Discovery of a Be X-Ray Pulsar in the SMC: AX J0051-733. https://doi.org/10.1093/pasj%2F51.6.l15

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