A Close Look at the State Transitions of Galactic Black Hole Transients during Outburst Decay

2004 ◽  
Vol 603 (1) ◽  
pp. 231-241 ◽  
Author(s):  
E. Kalemci ◽  
J. A. Tomsick ◽  
R. E. Rothschild ◽  
K. Pottschmidt ◽  
P. Kaaret
2000 ◽  
Vol 544 (1) ◽  
pp. 443-452 ◽  
Author(s):  
A. R. Rao ◽  
J. S. Yadav ◽  
B. Paul

2005 ◽  
Vol 622 (1) ◽  
pp. 508-519 ◽  
Author(s):  
E. Kalemci ◽  
J. A. Tomsick ◽  
M. M. Buxton ◽  
R. E. Rothschild ◽  
K. Pottschmidt ◽  
...  

2006 ◽  
Vol 639 (1) ◽  
pp. 340-347 ◽  
Author(s):  
E. Kalemci ◽  
J. A. Tomsick ◽  
R. E. Rothschild ◽  
K. Pottschmidt ◽  
S. Corbel ◽  
...  

2020 ◽  
Vol 496 (2) ◽  
pp. 1001-1012 ◽  
Author(s):  
V A Cúneo ◽  
K Alabarta ◽  
L Zhang ◽  
D Altamirano ◽  
M Méndez ◽  
...  

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.


Author(s):  
Satoshi Nakahira ◽  
Megumi Shidatsu ◽  
Kazuo Makishima ◽  
Yoshihiro Ueda ◽  
Kazutaka Yamaoka ◽  
...  

2021 ◽  
Vol 502 (1) ◽  
pp. L72-L78
Author(s):  
K Mohamed ◽  
E Sonbas ◽  
K S Dhuga ◽  
E Göğüş ◽  
A Tuncer ◽  
...  

ABSTRACT Similar to black hole X-ray binary transients, hysteresis-like state transitions are also seen in some neutron-star X-ray binaries. Using a method based on wavelets and light curves constructed from archival Rossi X-ray Timing Explorer observations, we extract a minimal timescale over the complete range of transitions for 4U 1608-52 during the 2002 and 2007 outbursts and the 1999 and 2000 outbursts for Aql X-1. We present evidence for a strong positive correlation between this minimal timescale and a similar timescale extracted from the corresponding power spectra of these sources.


1998 ◽  
Vol 184 ◽  
pp. 65-66
Author(s):  
Marc Freitag ◽  
Willy Benz

Massive but invisible black holes (BH) are often assumed to lurk in the center of many galaxies but definitive proof of their existence has not yet been established. However, in the surrounding stellar cluster stars are unavoidably being destroyed by tidal disruptions and stellar collisions liberating of order 1M⊙ in each event. The subsequent accretion of this gas by the BH could bring it back to “life” and reveal its presence.


1993 ◽  
Vol 30 (02) ◽  
pp. 365-372 ◽  
Author(s):  
Søren Asmussen ◽  
Ger Koole

A Markovian arrival stream is a marked point process generated by the state transitions of a given Markovian environmental process and Poisson arrival rates depending on the environment. It is shown that to a given marked point process there is a sequence of such Markovian arrival streams with the property that as m →∞. Various related corollaries (involving stationarity, convergence of moments and ergodicity) and counterexamples are discussed as well.


2007 ◽  
Vol 22 (10) ◽  
pp. 1875-1898 ◽  
Author(s):  
ORHAN DÖNMEZ

We investigate the special cases of the formation of shocks in the accretion disks around the nonrotating (Schwarzschild) black holes in cases where one or few stars perturb the disk. We model the structure of disk with a 2D fully general relativistic hydrodynamic code and investigate a variety of cases in which the stars interacting with the disk are captured at various locations. We have found the following results: (1) if the stars perturb the disk at nonsymmetric locations, a moving one-armed spiral shock wave is produced and it destroys the disk eventually; (2) if the disk is perturbed by a single star located close to the black hole, a standing shock wave is produced while the disk becomes an accretion tori; (3) if the disk is perturbed by stars at symmetric locations, moving two-armed spiral shock waves are produced while the disk reaches a steady state; (4) continuous injection of matter into the stable disk produces a standing shock wave behind the black hole. Our outcomes reinforce the view that different perturbations on the stable accretion disk carry out different types of shock waves which produce Quasi-Periodic Oscillation (QPO) phenomena in galactic black hole candidates and it is observed as a X-ray.


2002 ◽  
pp. 2279-2288 ◽  
Author(s):  
SANDIP K. CHAKRABARTI ◽  
S.G. MANICKAM ◽  
A. NANDI ◽  
A.R. RAO

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