A Swift view on IGR~J19149+1036

TL;DR

This paper analyzes 103 months of Swift BAT data on IGR J19149+1036, revealing its orbital period, spectral characteristics, and magnetic field, contributing to understanding high mass X-ray binaries.

Contribution

It provides the first long-term timing and spectral analysis of IGR J19149+1036, including detection of its orbital period and magnetic field estimation.

Findings

Detected a 22.25-day orbital period.

Identified a cyclotron absorption feature at 31 keV.

Estimated the neutron star's magnetic field as ~3.6 x 10^12 G.

Abstract

IGR~J19149+1036 is a high mass X-ray binary detected by INTEGRAL in 2011 in the hard X-ray domain. We have analyzed the 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+/- 0.05 d, 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 XRT spectra from the pointed follow up observations. The spectrum is adequately modeled 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 B_surf ~ 3.6 x 10^12 gauss.