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Here we study a 1–200 keV energy spectrum of the black hole binary Cygnus X-1 taken with NuSTAR and Suzaku. This is the first report of a NuSTAR observation of Cyg X-1 in the intermediate state, and the observation was taken during the part of the binary orbit where absorption due to the companion’s stellar wind is minimal. The spectrum includes a multi-temperature thermal disk component, a cutoff power-law component, and relativistic and nonrelativistic reflection components. Our initial fits with publicly available constant density reflection models (relxill and reflionx) lead to extremely high iron abundances (>9.96 and times solar, respectively). Although supersolar iron abundances have been reported previously for Cyg X-1, our measurements are much higher and such variability is almost certainly unphysical. Using a new version of reflionx that we modified to make the electron density a free parameter, we obtain better fits to the spectrum even with solar iron abundances. We report on how the higher density ( cm−3) impacts other parameters such as the inner radius and inclination of the disk. [ABSTRACT FROM AUTHOR]

We present results from the Nuclear Spectroscopic Telescope Array observations of the new black hole X-ray binary candidate MAXI J1631–479 at two epochs during its 2018–2019 outburst, which caught the source in a disk dominant state and a power-law dominant state. Strong relativistic disk reflection features are clearly detected, displaying significant variations in the shape and strength of the broad iron emission line between the two states. Spectral modeling of the reflection spectra reveals that the inner radius of the optically thick accretion disk evolves from <1.9 to 12 ± 1 rg (statistical errors at 90% confidence level) from the disk dominant to the power-law dominant state. Assuming in the former case that the inner disk radius is consistent with being at the innermost stable circular orbit, we estimate a black hole spin of a* > 0.94. Given that the bolometric luminosity is similar in the two states, our results indicate that the disk truncation observed in MAXI J1631–479 in the power-law dominant state is unlikely to be driven by a global variation in the accretion rate. We propose that it may instead arise from local instabilities in the inner edge of the accretion disk at high accretion rates. In addition, we find an absorption feature in the spectra centered at 7.33 ± 0.03 keV during the disk dominant state, which is evidence for the rare case that an extremely fast disk wind () is observed in a low-inclination black hole binary, with the viewing angle of 29° ± 1° as determined by the reflection modeling. [ABSTRACT FROM AUTHOR]

The Seyfert galaxy Mrk 335 is known for its frequent changes of flux and spectral shape in the X-ray band that occurred during recent years. These variations may be explained by the onset of a wind that previous, noncontemporaneous high-resolution spectroscopy in X-ray and UV bands located at accretion disk scale. A simultaneous new campaign by XMM-Newton and the Hubble Space Telescope (HST) caught the source at a historically low flux in the X-ray band. The soft X-ray spectrum is dominated by prominent emission features and by the effect of a strong ionized absorber with an outflow velocity of (5–6) × 103 km s−1. The broadband spectrum obtained by the EPIC-pn camera reveals the presence of an additional layer of absorption by gas at moderate ionization covering ∼80% of the central source, as well as tantalizing evidence for absorption in the Fe K band outflowing at the same velocity of the soft X-ray absorber. The HST Cosmic Origins Spectrograph spectra confirm the simultaneous presence of broad absorption troughs in C iv, Lyα, Lyβ, and O vi, with velocities of the order of 5000 km s−1 and covering factors in the range of 20%–30%. Comparison of the ionic column densities and of other outflow parameters in the two bands shows that the X-ray and UV absorbers are likely originated by the same gas. The resulting picture from this latest multiwavelength campaign confirms that Mrk 335 undergoes the effect of a patchy, medium-velocity outflowing gas in a wide range of ionization states that seem to be persistently obscuring the nuclear continuum. [ABSTRACT FROM AUTHOR]

Broad Fe K emission lines have been widely observed in the X-ray spectra of black hole systems as well as in neutron star systems. The intrinsically narrow Fe K fluorescent line is generally believed to be part of the reflection spectrum originating in an illuminated accretion disk which is broadened by strong relativistic effects. However, the nature of the lines in neutron star low-mass X-ray binaries (LMXBs) has been a matter of debate. We therefore obtained the longest, high-resolution X-ray spectrum of a neutron star LMXB to date with a 300 ks Chandra High Energy Transmission Grating Spectrometer (HETGS) observation of Serpens X-1. The observation was taken under the “continuous clocking” mode, and thus was free of photon pile-up effects. We carry out a systematic analysis and find that the blurred reflection model fits the Fe line of Serpens X-1 significantly better than a broad Gaussian component does, implying that the relativistic reflection scenario is much preferred. Chandra HETGS also provides a highest spectral resolution view of the Fe K region and we find no strong evidence for additional narrow lines. [ABSTRACT FROM AUTHOR]