Multiwaveband studies of the hard ROSAT SMC transient 1WGA J0053.8-7226: a new X-ray pulsar

D. A. H. Buckley; M. J. Coe; J. B. Stephens; K. van der Heyden; L. Angelini; N. White; P. Giommi

doi:10.1046/j.1365-8711.2001.03982.x

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arXiv · astro-ph/0008486

Multiwaveband studies of the hard ROSAT SMC transient 1WGA J0053.8-7226: a new X-ray pulsar

D. A. H. Buckley·M. J. Coe·J. B. Stephens·K. van der Heyden·L. Angelini·N. White·P. Giommi

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Abstract

We report on two optical candidates for the counterpart to an X-ray source in the SMC, 1WGA J0053.8-7226, identified as a serendipitous X-ray source from the ROSAT PSPC archive, and also observed by the Einstein IPC. Its X-ray properties, namely the hard X-ray spectrum, flux variability and column density indicate a hard, transient source, with a luminosity of 3.8 x 10E35 ergs/sec. XTE and ASCA observations have confirmed the source to be an X-ray pulsar, with a 46 s spin period. Our optical observations reveal two possible candidates within the error circle. Both exhibit strong H alpha and weaker H beta emission. The optical colours indicate that both objects are Be-type stars. The Be nature of the stars implies that the counterpart is most likely a Be/X-ray binary system. Subsequent IR photometry JHK of one of the objects shows the source varies by at least 0.5 mag, while the (J-K) measured nearly simultaneously with the UBVRI and spectroscopic observations indicate an IR-excess of approximately 0.3 magnitudes.

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D. A. H. Buckley, M. J. Coe, J. B. Stephens, K. van der Heyden, L. Angelini, N. White, P. Giommi. 2000-08-31. Multiwaveband studies of the hard ROSAT SMC transient 1WGA J0053.8-7226: a new X-ray pulsar. https://doi.org/10.1046/j.1365-8711.2001.03982.x

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