1209.2780 (Sergey Trudolyubov)

XMM-Newton discovery of transient 285.4 s X-ray pulsar XMMU J013359.5+303634 in M33    [PDF]

Sergey Trudolyubov

We report on the discovery and analysis of the transient X-ray pulsar XMMU J013359.5+303634 detected in the 2010 July-August deep XMM-Newton observations of the nearby spiral galaxy M33. The X-ray source exhibits pulsations with a period P~285.4 s and pulsed fraction ~47 per cent in the 0.3-10 keV energy band. The X-ray spectrum of XMMU J013359.5+303634 is hard and is well fitted with an absorbed simple power law of photon index Gamma~1.2 in the 0.3-10 keV energy band. The X-ray properties of the source and the absence of an optical counterpart brighter than 20 mag suggest that XMMU J013359.5+303634 is not a Galactic foreground object and probably belongs to M33. The maximum observed luminosity of the source in the 0.3-10 keV energy range is ~1.4e37 ergs/s at 817 kpc, at least 20 times higher than quiescent luminosity. Based on the transient behavior, overall X-ray properties and possible optical counterpart, we classify XMMU J013359.5+303634 as a Be/X-ray binary candidate.

View original: http://arxiv.org/abs/1209.2780