XMM-Newton and INTEGRAL analysis of the Supergiant Fast X-ray Transient IGR J17354-3255

Abstract

We present the results of combined INTEGRALand XMM-Newton observations of the supergiant fast X-ray transient (SFXT) IGR J17354-3255. Three XMM-Newton observations of lengths 33.4, 32.5, and 21.9 ks were undertaken, the first an initial pointing to identify the correct source in the field of view and the latter two performed around periastron. Simultaneous INTEGRALobservations across {∼ }66 {{per cent}} of the orbital cycle were analysed but the source was neither detected by IBIS/ISGRI nor by JEM-X. The XMM-Newton light curves display a range of moderately bright X-ray activity but there are no particularly strong flares or outbursts in any of the three observations. We show that the spectral shape measured by XMM-Newton can be fitted by a consistent model throughout the observation, suggesting that the observed flux variations are driven by obscuration from a wind of varying density rather than changes in accretion mode. The simultaneous INTEGRALdata rule out simple extrapolation of the simple power-law model beyond the XMM-Newton energy range.