2015MNRAS.446.1041C

IGR J19149+1036 is a high-mass X-ray binary detected by INTEGRAL in 2011 in the hard X-ray domain. We have analysed the Burst Alert Telescope (BAT) survey data of the first 10³ months of the Swift mission detecting this source at a significance level of ∼ 30 standard deviations. The timing analysis on the long-term BAT light curve reveals the presence of a strong sinusoidal intensity modulation of 22.25±0.05d, that we interpret as the orbital period of this binary system. A broad-band (0.3-150 keV) spectral analysis was performed combining the BAT spectrum and the X-Ray Telescope (XRT) spectra from the pointed follow-up observations. The spectrum is adequately modelled with an absorbed power law with a high-energy cutoff at ∼ 24 keV and an absorption cyclotron feature at ∼ 31 keV. Correcting for the gravitational redshift, the inferred magnetic field at the neutron star surface is Bsurf ∼ 3.6x10¹² G.