Discovery and study of the accreting pulsar 2RXP J130159.6-635806

Abstract

We report on analysis of the poorly studied source 2RXP J130159.6-635806 at different epochs with ASCA, BeppoSAX, XMM-Newton and INTEGRAL. The source shows coherent X-ray pulsations at a period ~700 s with an average spin-up rate of about . A broad-band (1-60 keV) spectral analysis of 2RXP J130159.6-635806 based on almost simultaneous XMM-Newton and INTEGRAL data demonstrates that the source has a spectrum typical of an accretion-powered X-ray pulsar, i.e. an absorbed power law with a high-energy cut-off with a photon index Γ~ 0.5-1.0 and a cut-off energy of ~25 keV. The long-term behaviour of the source, its spectral and timing properties, tend to indicate a high-mass X-ray binary with a Be companion. We also report on the identification of the likely infrared counterpart to 2RXP J130159.6-635806. The interstellar reddening does not allow us to strongly constrain the spectral type of the counterpart. The latter is, however, consistent with a Be star, the kind of which is often observed in accretion-powered X-ray pulsars.