Swift discovery of the orbital period of the high mass X-ray binary IGR J015712-7259 in the Small Magellanic Cloud
Abstract
Context. In the past few years, the hard X-ray astronomy has made a significant step forward, thanks to the monitoring of the IBIS/ISGRI telescope onboard the INTEGRAL satellite and of the Burst Alert Telescope (BAT) onboard the Swift observatory. This has provided a huge amount of novel information on many classes of sources.
Aims: We have been exploiting the BAT survey data to study the variability and the spectral properties of the new high mass X-ray binary sources detected by INTEGRAL. We investigate the properties of IGR J015712-7259.
Methods: We performed timing analysis on the 88-month BAT survey data and on the XRT pointed observations of this source. We also report on the broad-band 0.2-150 keV spectral analysis.
Results: We find evidence of a modulation of the hard-X-ray emission with period Po = 35.6 d. The significance of this modulation is 6.1 standard deviations. The broad band spectrum is modeled with an absorbed power law with photon index Γ ~ 0.4 and a steepening in the BAT energy range modeled with a cutoff at an energy of ~13 keV.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 2013
- DOI:
- 10.1051/0004-6361/201321897
- arXiv:
- arXiv:1305.3920
- Bibcode:
- 2013A&A...557A.113S
- Keywords:
-
- X-rays: individuals: IGR J0157127259;
- X-rays: binaries;
- binaries: close;
- stars: neutron;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 4 pages, 7 figures, accepted for publication on A&