AnXMM-Newtonview of FeKαin high-mass X-ray binaries

Abstract

We present a comprehensive analysis of the whole sample of available XMM-Newton observations of high-mass X-ray binaries (HMXBs) until August 2013, focusing on the FeKα emission line. This line is key to better understanding the physical properties of the material surrounding the X-ray source within a few stellar radii (the circumstellar medium). We collected observations from 46 HMXBs and detected FeKα in 21 of them. We used the standard classification of HMXBs to divide the sample into different groups. We find that (1) (4) We observe an inverse correlation between the X-ray luminosity and the equivalent width of FeKα (EW). This phenomenon is known as the X-ray Baldwin effect. (5) FeKα is narrow (σ line < 0.15 keV), reflecting that the reprocessing material does not move at high speeds. We attempt to explain the broadness of the line in terms of three possible broadening phenomena: line blending, Compton scattering, and Doppler shifts (with velocities of the reprocessing material V ∼ 1000 km s −1 ). (6) The equivalent hydrogen column (N H ) directly correlates to the EW of FeKα, displaying clear similarities to numerical simulations. It highlights the strong link between the absorbing and the fluorescent matter. (7) The observed N H in supergiant X-ray binaries (SGXBs) is in general higher than in supergiant fast X-ray transients (SFXTs). We suggest two possible explanations: different orbital configurations or a different interaction compact object -wind. (8) Finally, we analysed the sources IGR J16320-4751 and 4U 1700-37 in more detail, covering several orbital phases. The observed variation in N H between phases is compatible with the absorption produced by the wind of their optical companions. The results clearly point to a very important contribution of the donor's wind in the FeKα emission and the absorption when the donor is a supergiant massive star.

Multi-wavelength observations of IGR J17544-2619 from quiescence to outburst

“…A weak iron K α line at 6.4 keV was detected in the spectra averaged over the entire observational period. This is likely produced by fluorescence due to the X-ray illumination of the stellar wind material surrounding the compact object hosted in IGR J17544-2619, as the measured equivalent width is relatively small and comparable to that observed in a large number of wind-fed HMXBs (see, e.g., Bozzo et al 2008;Torrejón et al 2010;Manousakis & Walter 2011;Giménez-García et al 2015, and references therein). We summarize all results obtained with the phenomenological model in Table 3 and show in Fig.…”

X-ray spectral parameters for a sample of 95 active galactic nuclei

“…Dadina 2008, De Rosa et al 2012, Winter et al 2009, Ballantyne, 2014. On the other hand, the effect the decreasing dependence of FeK EW of the luminosity has been claimed (Bianchi et al 2007;Dadina 2008;Page et al 2004, Ricci 2013, Gimenez-Garcia et al, 2015 for the Seyfert1s in the range of 2 10 keV . Recently, Baldwin effect has been reported for Seyfert2s using the Suzaku data (Fukuzawa et al 2011) and both for Suzaku and XMM-Newton data (Ricci et al 2014b and references therein).…”

Chandra Observations of Eight Sources Discovered by Integral

“…The sourceʼs X-ray luminosity could provide a way to distinguish between the different hypotheses because CV/IPs are not known to exceed values of ∼10 35 erg s Giménez-García et al 2015), these only occur in cases where the continuum is absorbed by material intrinsic to the system (e.g., a stellar wind), but the low N H for IGRJ14091-6108 makes this possibility unlikely. While an EW of 1.2 keV is also somewhat high for a CV, values in excess of 400 eV (combining all iron ionization states) are not unusual (Hellier & Mukai 2004).…”