Search

We find soft X-ray emission lines from the X-ray binary Swift J1858.6–0814 in data from XMM–Newton Reflection Grating Spectrometer (RGS): N  vii , O  vii , and O  viii , as well as notable residuals short of a detection at Ne  ix and other higher ionization transitions. These could be associated with the disc atmosphere, as in accretion disc corona sources, or with a wind, as has been detected in Swift J1858.6–0814 in emission lines at optical wavelengths. Indeed, the N  vii line is redshifted, consistent with being the emitting component of a P-Cygni profile. We find that the emitting plasma has an ionization parameter log (ξ) = 1.35 ± 0.2 and a density n > 1.5 × 1011 cm−3. From this, we infer that the emitting plasma must be within 1013 cm of the ionizing source, ∼5 × 107 rg for a 1.4 M⊙ neutron star, and from the line width that it is at least 104 rg away [2 × 109(M /1.4 M⊙) cm]. We compare this with known classes of emission-line regions in other X-ray binaries and active galactic nuclei. [ABSTRACT FROM AUTHOR]

We present a detailed analysis of three XMM–Newton observations of the black hole low-mass X-ray binary IGR J17091−3624 taken during its 2016 outburst. Radio observations obtained with the Australia Telescope Compact Array indicate the presence of a compact jet during all observations. From the best X-ray data fit results, we concluded that the observations were taken during a transition from a hard accretion state to a hard-intermediate accretion state. For Observations 1 and 2, a local absorber can be identified in the EPIC-pn spectra but not in the RGS spectra, preventing us from distinguishing between absorption local to the source and that from the hot ISM component. For Observation 3, on the other hand, we have identified an intrinsic ionized static absorber in both EPIC-pn and RGS spectra. The absorber, observed simultaneously with a compact jet emission, is characterized by an ionization parameter of 1.96 < log ξ < 2.05 and traced mainly by Ne  x , Mg  xii , Si  xiii , and Fe  xviii. [ABSTRACT FROM AUTHOR]

In the last decade, X-ray spectroscopy has enabled a wealth of discoveries of photoionised absorbers in X-ray binaries. Studies of such accretion disc atmospheres and winds are of fundamental importance to understand accretion processes and possible feedback mechanisms to the environment. In this work, we review the current observational state and theoretical understanding of accretion disc atmospheres and winds in low-mass X-ray binaries, focusing on the wind launching mechanisms and on the dependence on accretion state. We conclude with issues that deserve particular attention. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]