2007A&A...469.1063I

Serendipitous and dedicated observations with the Rossi X-ray Timing Explorer (RXTE) and the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) were analyzed to study the transient high-mass X-ray binary IGR J00370+6122, in particular to search for an accretion-powered pulsar as companion to the optically identified (Reig et al., 2005A&A...440..637R) B0.5 II-III donor star. Highly variable fluxes were measured in the RXTE data during outbursts of up to 2.2x10^–10erg/cm2/s (3-20keV; averaged over 1h). During a 1-h time span with RXTE flaring activity was detected with an oscillating signal repeating 7 times. Epoch folding reveals a 346±6s period. We propose that this is the period of the putative pulsar. This measurement puts the source in the wind-fed accretion region of the P_orb (=15.7d) versus P_pulse ``Corbet'' diagram. The 3 to 60keV flare spectrum was modeled with an absorbed power law and the absorption column was found to be 15-20 times larger than the interstellar value and the value obtained for the optical counterpart, suggesting an accretor embedded in the wind of the donor star.