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

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.

6 pages, 5 figures, accepted for publication in PASJ

Cited by in corpus (12)

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• Criteria for Dynamical Timescale Mass Transfer of Metal-poor Intermediate-mass Stars
• Observations of the unusual counterpart to the X-ray pulsar AX J0051-733
• Photometric Periodicities of Be/X-ray Pulsars in the Small Magellanic Cloud
• Constraining compactness and magnetic field geometry of X-ray pulsars from the statistics of their pulse profiles
• Neutron Stars and Black Holes in the Small Magellanic Cloud: The SMC NuSTAR Legacy Survey
• A Puzzling Paucity of Double Peaked X-ray Pulsars
• Radiative Column and Light Curve of X-Ray Binary Pulsars
• A Discovery of a Peculiar Pulsar in the Small Magellanic Cloud
• A 168-s X-Ray Pulsar in the SMC Observed with ASCA