IGR J18179-1621: an obscured X-ray pulsar discovered by INTEGRAL

Abstract

We report on all the INTEGRAL and Swift data collected during the first outburst observed from IGR J18179-1621. The broad-band spectral analysis showed that the X-ray emission from the source is heavily absorbed (N_H ≃ 10²³ cm^-2), and well-described by a flat power-law with a high energy rollover (cutoff energy 9-12 keV, e-folding energy 4-7 keV). We found some evidence of a cyclotron absorption feature at 22 ± 1 keV. Together with the pulsations at 11.8 s discovered in the XRT data, this evidence would suggest that IGR J18179-1621 is an obscured, magnetized, accreting neutron star that is possibly part of a supergiant high-mass X-ray binary or a Be X-ray binary system.

Appendix A is available in electronic form at http://www.aanda.org