scholarly journals On the nature of the X-ray corona of black hole binaries in the hard state

2011 ◽  
Author(s):  
Julien Malzac
Keyword(s):  
Black Hole ◽  
X Ray ◽  
Black Hole Binaries ◽  
Hard State

scholarly journals Thermal and radiation driving can produce observable disc winds in hard-state X-ray binaries

2020 ◽  
Vol 492 (4) ◽  
pp. 5271-5279 ◽  
Author(s):  
Nick Higginbottom ◽  
Christian Knigge ◽  
Stuart A Sim ◽  
Knox S Long ◽  
James H Matthews ◽  
...  
Keyword(s):  
Black Hole ◽  
Binary Systems ◽  
Velocity Structure ◽  
Spectral Energy ◽  
X Ray ◽  
Black Hole Binaries ◽  
Soft State ◽  
Before And After ◽  
Hard State ◽  
New Generation

ABSTRACT X-ray signatures of outflowing gas have been detected in several accreting black hole binaries, always in the soft state. A key question raised by these observations is whether these winds might also exist in the hard state. Here, we carry out the first full-frequency radiation hydrodynamic simulations of luminous (${L = 0.5 \, L_{\mathrm{\mathrm{ Edd}}}}$) black hole X-ray binary systems in both the hard and the soft state, with realistic spectral energy distributions (SEDs). Our simulations are designed to describe X-ray transients near the peak of their outburst, just before and after the hard-to-soft state transition. At these luminosities, it is essential to include radiation driving, and we include not only electron scattering, but also photoelectric and line interactions. We find powerful outflows with ${\dot{M}_{\mathrm{ wind}} \simeq 2 \, \dot{M}_{\mathrm{ acc}}}$ are driven by thermal and radiation pressure in both hard and soft states. The hard-state wind is significantly faster and carries approximately 20 times as much kinetic energy as the soft-state wind. However, in the hard state the wind is more ionized, and so weaker X-ray absorption lines are seen over a narrower range of viewing angles. Nevertheless, for inclinations ≳80°, blueshifted wind-formed Fe xxv and Fe xxvi features should be observable even in the hard state. Given that the data required to detect these lines currently exist for only a single system in a luminous hard state – the peculiar GRS 1915+105 – we urge the acquisition of new observations to test this prediction. The new generation of X-ray spectrometers should be able to resolve the velocity structure.

ON THE NATURE OF THE X-RAY CORONA OF BLACK HOLE BINARIES

2012 ◽  
Vol 08 ◽  
pp. 73-83 ◽  
Author(s):  
JULIEN MALZAC
Keyword(s):  
Black Hole ◽  
High Energy ◽  
State Transitions ◽  
Physical Parameters ◽  
X Ray ◽  
Black Hole Binaries ◽  
Accretion Flow ◽  
Recent Developments ◽  
Hard State ◽  
Radiation Processes

We discuss the nature of the X-ray emitting plasma of black hole binaries. It is well known that the temperature and optical depth of the Comptonising electrons of the X-ray corona of black hole binaries can be measured using spectroscopy in the 1 keV-1 MeV energy band. We emphasize recent developments in the modeling of high energy radiation processes which allow us to constrain other important physical parameters of the corona, such as the strength of magnetic field, or the temperature of the ions. The results appear to challenge current accretion models. In particular, standard advection dominated accretion flow do not match the observed properties of bright hard state X-ray binaries such as Cygnus X-1 or GX 339-4. On the other hand, we find that all the data would be consistent with a multi-zone magnetically dominated hot accretion flow model. We also emphasize that besides the usual spectral state transitions observed at luminosities above a few percent of Eddington, there is observational evidence for at least two additional, more subtle, radiative transitions occuring at lower luminosities.

scholarly journals GRS1915+105: a comparison of the plateau state to the canonical hard state

2010 ◽  
Vol 6 (S275) ◽  
pp. 294-298 ◽  
Author(s):  
Pieter van Oers ◽  
Sera Markoff
Keyword(s):  
Black Hole ◽  
Near Infrared ◽  
Model Parameters ◽  
Data Sets ◽  
X Ray ◽  
Black Hole Binaries ◽  
Hard State ◽  
Multi Wavelength ◽  
Plateau State ◽  
The Relationship

AbstractGRS 1915+105 is a very peculiar black hole binary that exhibits accretion-related states that are not observed in any other stellar-mass black hole system. One of these states, however – referred to as the plateau state – may be related to the canonical hard state of black hole X-ray binaries. Both the plateau and hard state are associated with steady, relatively lower X-ray emission and flat/inverted radio emission, that is sometimes resolved into compact, self-absorbed jets. To investigate the relationship between the plateau and the hard state, we fit two multi-wavelength observations using a steady-state outflow-dominated model, developed for hard state black hole binaries. The data sets consist of quasi-simultaneous observations in radio, near-infrared and X-ray bands. Interestingly, we find both significant differences between the two plateau states, as well as between the best-fit model parameters and those representative of the hard state. We discuss our interpretation of these results, and the possible implications for GRS 1915+105's relationship to canonical black hole candidates.

scholarly journals An additional soft X-ray component in the dim low/hard state of black hole binaries

2010 ◽  
Vol 403 (3) ◽  
pp. 1102-1112 ◽  
Author(s):  
C. Y. Chiang ◽  
Chris Done ◽  
M. Still ◽  
O. Godet
Keyword(s):  
Black Hole ◽  
X Ray ◽  
Black Hole Binaries ◽  
Hard State

scholarly journals A NICER look at the state transitions of the black hole candidate MAXI J1535−571 during its reflares

2020 ◽  
Vol 496 (2) ◽  
pp. 1001-1012 ◽  
Author(s):  
V A Cúneo ◽  
K Alabarta ◽  
L Zhang ◽  
D Altamirano ◽  
M Méndez ◽  
...  
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Timing Analysis ◽  
The State ◽  
State Transitions ◽  
X Ray ◽  
Black Hole Binaries ◽  
Black Hole Candidate ◽  
Hard State ◽  
Higher Sensitivity

ABSTRACT The black hole candidate and X-ray binary MAXI J1535−571 was discovered in 2017 September. During the decay of its discovery outburst, and before returning to quiescence, the source underwent at least four reflaring events, with peak luminosities of ∼1035–36 erg s−1 (d/4.1 kpc)2. To investigate the nature of these flares, we analysed a sample of NICER (Neutron star Interior Composition Explorer) observations taken with almost daily cadence. In this work, we present the detailed spectral and timing analysis of the evolution of the four reflares. The higher sensitivity of NICER at lower energies, in comparison with other X-ray detectors, allowed us to constrain the disc component of the spectrum at ∼0.5 keV. We found that during each reflare the source appears to trace out a q-shaped track in the hardness–intensity diagram similar to those observed in black hole binaries during full outbursts. MAXI J1535−571 transits between the hard state (valleys) and softer states (peaks) during these flares. Moreover, the Comptonized component is undetected at the peak of the first reflare, while the disc component is undetected during the valleys. Assuming the most likely distance of 4.1 kpc, we find that the hard-to-soft transitions take place at the lowest luminosities ever observed in a black hole transient, while the soft-to-hard transitions occur at some of the lowest luminosities ever reported for such systems.

scholarly journals MAXI J1820+070 with NuSTAR I. An increase in variability frequency but a stable reflection spectrum: coronal properties and implications for the inner disc in black hole binaries

2019 ◽  
Vol 490 (1) ◽  
pp. 1350-1362 ◽  
Author(s):  
D J K Buisson ◽  
A C Fabian ◽  
D Barret ◽  
F Fürst ◽  
P Gandhi ◽  
...  
Keyword(s):  
Black Hole ◽  
Low Frequency ◽  
Periodic Oscillation ◽  
Thermal Electron ◽  
X Ray ◽  
Black Hole Binaries ◽  
Black Hole Candidate ◽  
Long Duration ◽  
Hard State ◽  
Characteristic Features

ABSTRACT MAXI J1820+070 (optical counterpart ASASSN-18ey) is a black hole candidate discovered through its recent very bright outburst. The low extinction column and long duration at high flux allow detailed measurements of the accretion process to be made. In this work, we compare the evolution of X-ray spectral and timing properties through the initial hard state of the outburst. We show that the inner accretion disc, as measured by relativistic reflection, remains steady throughout this period of the outburst. Nevertheless, subtle spectral variability is observed, which is well explained by a change in coronal geometry. However, characteristic features of the temporal variability – low-frequency roll-over and quasi-periodic oscillation frequency – increase drastically in frequency, as the outburst proceeds. This suggests that the variability time-scales are governed by coronal conditions rather than solely by the inner disc radius. We also find a strong correlation between X-ray luminosity and coronal temperature. This can be explained by electron pair production with a changing effective radius and a non-thermal electron fraction of $\sim 20$ per cent.

X-ray spectral and timing studies of black hole transients in the hard state at low luminosity

2012 ◽  
Author(s):  
John A. Tomsick ◽  
Kazutaka Yamaoka ◽  
Emrah Kalemci ◽  
Stéphane Corbel ◽  
Philip Kaaret ◽  
...  
Keyword(s):  
Black Hole ◽  
X Ray ◽  
Hard State

scholarly journals Energy and time-lag spectra of galactic black-hole X-ray sources in the low/hard state

2003 ◽  
Vol 403 (1) ◽  
pp. L15-L18 ◽  
Author(s):  
P. Reig ◽  
N. D. Kylafis ◽  
D. Giannios
Keyword(s):  
Black Hole ◽  
Time Lag ◽  
X Ray ◽  
Galactic Black Hole ◽  
Hard State
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