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Type I X-ray bursts, burst oscillations and kHz quasi-periodic oscillations in the neutron star system IGR J17191−2821 |
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| Authors: | D Altamirano M Linares A Patruno N Degenaar R Wijnands M Klein-Wolt M van der Klis C Markwardt J Swank |
| Institution: | Astronomical Institute, 'Anton Pannekoek', University of Amsterdam, Science Park 904, 1098XH Amsterdam, the Netherlands;Laboratory for High-Energy Astrophysics, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA;Department of Astronomy, University of Maryland, College Park, MD 20742, USA |
| Abstract: | We present a detailed study of the X-ray energy and power spectral properties of the neutron star transient IGR J17191?2821. We discovered four instances of pairs of simultaneous kilohertz quasi-periodic oscillations (kHz QPOs). The frequency difference between these kHz QPOs is between 315 and 362 Hz. We also report on the detection of five thermonuclear type I X-ray bursts and the discovery of burst oscillations at ～294 Hz during three of them. Finally, we report on a faint and short outburst precursor, which occurred about two months before the main outburst. Our results on the broad-band spectral and variability properties allow us to firmly establish the atoll source nature of IGR J17191?2821. |
| Keywords: | accretion accretion discs binaries: close stars: individual: IGR J17191?2821 stars: individual: XTE J1747?274 stars: neutron X-rays: stars |