X-ray energy spectra from accretion disks in black hole candidates

1994 ◽  
Author(s):  
Ken Ebisawa
Keyword(s):  
Black Hole ◽  
Accretion Disks ◽  
Energy Spectra ◽  
X Ray ◽  
Black Hole Candidates

On the spectral hardening factor of the X-ray emission from accretion disks in black hole candidates

1995 ◽  
Vol 445 ◽  
pp. 780 ◽  
Author(s):  
Toshiya Shimura ◽  
Fumio Takahara
Keyword(s):  
Black Hole ◽  
Accretion Disks ◽  
X Ray ◽  
Hardening Factor ◽  
Black Hole Candidates

scholarly journals Disk Oscillations as the Origin of Quasi-Periodic Oscillations in Black Hole Candidates

1998 ◽  
Vol 188 ◽  
pp. 381-381
Author(s):  
T. Yamasaki ◽  
S. Mineshige ◽  
S. Kato
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Accretion Disks ◽  
Galactic Nuclei ◽  
Linear Analysis ◽  
High State ◽  
Periodic Oscillations ◽  
X Ray ◽  
Very High ◽  
Black Hole Candidates

Quasi-periodic oscillations (QPOs) of a few Hz are observed in the very high state of some black hole candidates (GX 339-4 and GS 1124-68). This is the Kepler frequency at the radius of a few hundred Schwarzschild radii. As a possible mechanism of the QPOs in these objects, the trapped oscillations in the accretion disks are considered. The trapped oscillations of the disks were investigated by several authors. They studied the trapped oscillations in the standard radiative cooling-dominated disks. Recently, the advection-dominated accretion flow is considered, as a possible model to explain the hard X-ray spectra of the black hole candidates or the active galactic nuclei. In particular, in the very high state of some black hole candidates, the spectrum can be explained by the disk-corona model which comprises the cold standard accretion disk and the advection-dominated corona above the cold disk. We thus investigated the trapped axi-symmetric oscillations in the advection-dominated corona by the global linear analysis.

scholarly journals X-ray Irradiated Accretion Disk and Bimodal States

1987 ◽  
Vol 125 ◽  
pp. 247-247
Author(s):  
R. Hoshi ◽  
H. Inoue
Keyword(s):  
Black Hole ◽  
Accretion Disk ◽  
Accretion Disks ◽  
Spectroscopic Studies ◽  
X Ray ◽  
Black Hole Candidates

It is well known that black hole candidates, Cyg X-1 and GX 339-4, have distinct high and low states, known as bimodal states. Detailed spectroscopic studies of these X-ray sources have revealed high and low states corresponding to optically thick and thin states of the surrounding accretion disks.

scholarly journals Measuring the supermassive black hole parameters with space missions

2006 ◽  
Vol 2 (S238) ◽  
pp. 475-476
Author(s):  
Alexander F. Zakharov
Keyword(s):  
Black Hole ◽  
Spectral Line ◽  
Accretion Disks ◽  
Seyfert Galaxies ◽  
Emission Lines ◽  
X Ray ◽  
Line Shapes ◽  
Supermassive Black Hole ◽  
Broad Emission ◽  
Different Types

AbstractRecent X-ray observations of microquasars and Seyfert galaxies reveal broad emission lines in their spectra, which can arise in the innermost parts of accretion disks. Recently Müller & Camenzind (2004) classified different types of spectral line shapes and described their origin. Zakharov (2006b) clarified their conclusions about an origin of doubled peaked and double horned line shapes in the framework of a radiating annulus model and discussed s possibility to evaluate black hole parameters analyzing spectral line shapes.

scholarly journals Phase lags and coherence of X-ray variability in black hole candidates

1996 ◽  
Vol 280 (1) ◽  
pp. 227-234 ◽  
Author(s):  
M. A. Nowak ◽  
B. A. Vaughan
Keyword(s):  
Black Hole ◽  
X Ray ◽  
Phase Lags ◽  
Black Hole Candidates

scholarly journals Observational testability of a Kerr bound in the x-ray spectrum of black hole candidates

2010 ◽  
Vol 27 (7) ◽  
pp. 075003 ◽  
Author(s):  
Rohta Takahashi ◽  
Tomohiro Harada
Keyword(s):  
Black Hole ◽  
X Ray ◽  
Black Hole Candidates

Black-Hole Candidates in X-ray Binaries

2004 ◽  
Author(s):  
Philip A Charles
Keyword(s):  
Black Hole ◽  
X Ray ◽  
X Ray Binaries ◽  
Black Hole Candidates

Accretion Disks in Black Hole Candidates Observed with ASCA

1998 ◽  
pp. 135-138
Author(s):  
T. Dotani
Keyword(s):  
Black Hole ◽  
Accretion Disks ◽  
Black Hole Candidates

scholarly journals Recent Ginga Results on Galactic X-Ray Binaries

1992 ◽  
Vol 9 ◽  
pp. 211-215
Author(s):  
Y. Tanaka
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Related Problem ◽  
X Ray ◽  
Field Decay ◽  
X Ray Binaries ◽  
The Magnetic Field ◽  
Black Hole Candidates

AbstractBased on the recent Ginga results, following topics on X-ray binaries are briefly discussed: The cyclotron resonnance features observed from several X-ray pulsars, and related problem of the magnetic field decay. Search for millisec. pulsations from LMXRBs. Very bright transients which are suspected to be new black hole candidates, and an estimation of the number of such black hole sources in our galaxy.

scholarly journals Tracing Black Hole Signatures in Several Black Hole Candidates Based on Their X-Ray Spectral Evolution

2020 ◽  
Vol 240 ◽  
pp. 04001
Author(s):  
Fahmi Iman Alfarizki ◽  
Kiki Vierdayanti
Keyword(s):  
Black Hole ◽  
Compact Object ◽  
Spectral Evolution ◽  
Thermal Component ◽  
X Ray ◽  
Black Hole Candidate ◽  
Spectral Fitting ◽  
Transient Nature ◽  
Transient System ◽  
Black Hole Candidates

Investigation of spectral evolution of four black hole candidates was carried out by using color-color diagram as well as spectral fitting on Swift/XRT data. Newly found candidates, which are classified as low-mass X-ray binary system based on their transient nature, are the focus of our work. We compare their spectral evolutions to that of XTE J1752-223, a transient system and a more convincing black hole candidate whose mass has been determined from spectral-timing correlation scaling. In addition, comparison to Cygnus X-1, a well-known stellar-mass black hole, was done despite its persistent nature. The spectral fitting, by using a combination of thermal disk and non-thermal component model, results in the innermost temperature values in the range of the typical innermost temperature of black hole binary which is 0.7 – 1.5 keV. The spectral evolutions of the candidates bear a resemblance to both Cygnus X-1 and XTE J1752-223. We note that during Swift/XRT observations, the spectra of Cygnus X-1 and IGR J17451-3022 are mostly dominated by the non- thermal component. We conclude that the compact object of MAXI J1535- 571 and MAXI J1828-249 is highly likely to be a black hole. However, the lack of data rendered conclusive result impossible for IGR J17454-2919.

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