scholarly journals The hard X-ray spectral evolution in X-ray binaries and ULXs

2009 ◽  
Author(s):  
Qingwen Wu ◽  
Minfeng Gu
Keyword(s):  
Spectral Evolution ◽  
X Ray ◽  
X Ray Binaries

scholarly journals Revealing the Physical Changes Taking Place in Z-Track Motion in Low Mass X-Ray Binaries

2004 ◽  
Vol 194 ◽  
pp. 206-206
Author(s):  
M. Bałucińska-Church ◽  
M. J. Church ◽  
G. Halai ◽  
A. Szostek
Keyword(s):  
Neutron Star ◽  
Emission Model ◽  
Spectral Evolution ◽  
X Ray ◽  
Astrophysical Problem ◽  
Low Mass ◽  
Physical Changes ◽  
First Time ◽  
X Ray Binaries

The explanation of the strong physical changes clearly taking place in the Z-track class of Low Mass X-ray Binaries has so far not been obtained, and this remains a significant astrophysical problem, without which we cannot claim to understand accretion in LMXB. We have for the first time applied the Birmingham emission model (2,3) to this problem to attempt to obtain a solution from the spectral evolution along the Z-track in the source GX 340+0 observed with Rossi- ХTE. In this model, X-ray emission consists of blackbody from the neutron star, plus Comptonized emission from an extended ADC.

scholarly journals The obscured X-ray binaries V404 Cyg, Cyg X–3, V4641 Sgr, and GRS 1915+105

2020 ◽  
Vol 639 ◽  
pp. A13 ◽  
Author(s):  
K. I. I. Koljonen ◽  
J. A. Tomsick
Keyword(s):  
Large Scale ◽  
Surrounding Medium ◽  
The Other ◽  
Opening Angle ◽  
Spectral Evolution ◽  
Time Resolved ◽  
Orbital Inclination ◽  
X Ray ◽  
Geometrical Change ◽  
X Ray Binaries

Aims. V404 Cyg, Cyg X–3, V4641 Sgr, and GRS 1915+105 are among the brightest X-ray binaries and display complex behavior in their multiwavelength emission. Except for Cyg X–3, the other three sources have large accretion disks, and there is evidence of a high orbital inclination. Therefore, any large-scale geometrical change in the accretion disk can cause local obscuration events. On the other hand, Cyg X–3 orbits its Wolf-Rayet companion star inside the heavy stellar wind obscuring the X-ray source. We study here whether the peculiar X-ray spectra observed from all four sources can be explained by local obscuration events. Methods. We used spectra obtained with the Nuclear Spectroscopic Telescope Array and Rossi X-ray Timing Explorer to study the spectral evolution of the four luminous hard X-ray sources. We fit the time-averaged spectra, and also time-resolved spectra in case of V404 Cyg, with two physically motivated models describing either a scenario where all the intrinsic emission is reprocessed in the surrounding matter or where the emitter is surrounded by a thick torus with variable opening angle. Results. We show that the X-ray spectra during specific times are very similar in all four sources, likely arising from the high-density environments where they are embedded. The fitted models suggest that a low-luminosity phase preceding an intense flaring episode in the 2015 outburst of V404 Cyg is heavily obscured, but intrinsically very bright (super-Eddington) accretion state. Similar spectral evolution to that of V404 Cyg is observed from the recent X-ray state of GRS 1915+105 that presented unusually low luminosity. The modeling results point to a geometry change in the (outflowing) obscuring matter in V404 Cyg and GRS 1915+105, which is also linked to the radio (jet) evolution. Within the framework of the models, all sources display obscured X-ray emission, but with different intrinsic luminosities ranging from lower than 1% of the Eddington luminosity up to the Eddington limit. This indicates that different factors cause the obscuration. This work highlights the importance of taking the reprocessing of the X-ray emission in the surrounding medium into account in modeling the X-ray spectra. This may well take place in other sources as well.

scholarly journals GRS 1758–258: RXTE Monitoring of a Rare Persistent Hard State Black Hole

10.14311/1480 ◽  
2011 ◽  
Vol 51 (6) ◽  
Author(s):  
M. Obst ◽  
K. Pottschmidt ◽  
A. Lohfink ◽  
J. Wilms ◽  
M. Böck ◽  
...  
Keyword(s):  
Black Hole ◽  
State Transitions ◽  
Spectral Evolution ◽  
X Ray ◽  
Soft State ◽  
Hard State ◽  
Long Term Behavior ◽  
X Ray Binaries ◽  
Black Hole Candidates

GRS 1758–258 is the least studied of the three persistent black hole X-ray binaries in our Galaxy. It is also one of only two known black hole candidates, including all black hole transients, which shows a decrease of its 3-10 keV flux when entering the thermally dominated soft state, rather than an increase.We present the spectral evolution of GRS 1758–258 from RXTE-PCA observations spanning a time of about 11 years from 1996 to 2007. During this time, seven dim soft states are detected. We also consider INTEGRAL monitoring observations of the source and compare the long-term behavior to that of the bright persistent black hole X-ray binary Cygnus X-1. We discuss the observed state transitions in the light of physical scenarios for black hole transitions.

scholarly journals ON NEUTRAL ABSORPTION AND SPECTRAL EVOLUTION IN X-RAY BINARIES

2009 ◽  
Vol 707 (1) ◽  
pp. L77-L81 ◽  
Author(s):  
J. M. Miller ◽  
E. M. Cackett ◽  
R. C. Reis
Keyword(s):  
Spectral Evolution ◽  
X Ray ◽  
X Ray Binaries

scholarly journals THE X-RAY SPECTRAL EVOLUTION OF GALACTIC BLACK HOLE X-RAY BINARIES TOWARD QUIESCENCE

2013 ◽  
Vol 773 (1) ◽  
pp. 59 ◽  
Author(s):  
Richard. M. Plotkin ◽  
Elena Gallo ◽  
Peter G. Jonker
Keyword(s):  
Black Hole ◽  
Spectral Evolution ◽  
X Ray ◽  
Galactic Black Hole ◽  
X Ray Binaries

scholarly journals Microquasars: A Galactic-Extragalactic Connection?

2002 ◽  
Vol 19 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Kinwah Wu ◽  
Jason A. Stevens ◽  
Diana C. Hannikainen
Keyword(s):  
Radio Emission ◽  
Growth Phase ◽  
Radio Sources ◽  
Shock Model ◽  
Relativistic Jets ◽  
Spectral Evolution ◽  
X Ray ◽  
Radio Outburst ◽  
X Ray Binaries ◽  
Quasar 3C 273

AbstractMicroquasars are Galactic X-ray binaries which show radio emission from relativistic outflows. Here we argue that the origins of radio emission from microquasars and compact extragalactic radio sources are similar. In particular, both can be explained qualitatively by a model in which shocks are propagating in the relativistic jets. The microquasar GRO J1655–40 is used to illustrate that the spectral evolution of its 1994 radio outburst can be explained by the growth phase of the generalised-shock model, similar to the case of the quasar 3C 273.

scholarly journals A unified accretion-ejection paradigm for black hole X-ray binaries

2020 ◽  
Vol 640 ◽  
pp. A18
Author(s):  
G. Marcel ◽  
F. Cangemi ◽  
J. Rodriguez ◽  
J. Neilsen ◽  
J. Ferreira ◽  
...  
Keyword(s):  
Radio Emission ◽  
Low Frequency ◽  
Spectral Evolution ◽  
X Ray ◽  
Multi Wavelength ◽  
Normalisation Factor ◽  
Transition Radius ◽  
Type C ◽  
Activity Cycles ◽  
X Ray Binaries

Context. We proposed in paper I that the spectral evolution of transient X-ray binaries (XrB) is due to an interplay between two flows: a standard accretion disk (SAD) in the outer parts and a jet-emitting disk (JED) in the inner parts. We showed in papers II, III, and IV that the spectral evolution in X-ray and radio during the 2010–2011 outburst of GX 339-4 can be recovered. However, the observed variability in X-ray was never addressed in this framework. Aims. We investigate the presence of low frequency quasi-periodic oscillations (LFQPOs) during an X-ray outburst, and address the possible correlation between the frequencies of these LFQPOs and the transition radius between the two flows, rJ. Methods. We select X-ray and radio data that correspond to 3 outbursts of GX 339-4. We use the method detailed in Paper IV to obtain the best parameters rJ(t) and ṁin(t) for each outburst. We also independently search for X-ray QPOs in each selected spectra and compare the QPO frequency to the Kepler and epicyclic frequencies of the flow in rJ. Results. We successfully reproduce the correlated evolution of the X-ray spectra and the radio emission for 3 different activity cycles of GX 339-4. We use a unique normalisation factor for the radio emission, f∼R. We also report the detection of 7 new LFQPOs (3 Type B, and 4 Type C), to go along with the ones previously reported in the literature. We show that the frequency of Type C QPOs can be linked to the dynamical JED-SAD transition radius rJ, rather than to the optically thin-thick transition radius in the disk. The scaling factor q such that νQPO ≃ νK(rJ)/q is q ≃ 70 − 130, a factor consistent during the 4 cycles, and similar to previous studies. Conclusions. The JED-SAD hybrid disk configuration not only provides a successful paradigm allowing us to describe XrB cycles, but also matches the evolution of QPO frequencies. Type C QPOs provide an indirect way to probe the JED-SAD transition radius, where an undetermined process produces secular variability. The demonstrated relation between the transition radius links Type C QPOs to the transition between two different flows, effectively tying it to the inner magnetized structure, i.e., the jets. This direct connection between the jets’ (accretion-ejection) structure and the process responsible for Type C QPOs, if confirmed, could naturally explain their puzzling multi-wavelength behavior.

scholarly journals The X-ray spectral evolution and radio–X-ray correlation in radiatively efficient black-hole sources

2014 ◽  
Vol 10 (S312) ◽  
pp. 249-251
Author(s):  
Ai-Jun Dong ◽  
Qingwen Wu ◽  
Xiao-Feng Cao
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Spectral Evolution ◽  
Critical Flux ◽  
Fundamental Plane ◽  
X Ray ◽  
Data Points ◽  
X Ray Binaries

AbstractWe explore X-ray spectral evolution and radio–X-ray correlation simultaneously for four X-ray binaries (XRBs). We find that hard X-ray photon indices, Γ, are anti- and positively correlated to X-ray fluxes when the X-ray flux, F3–9keV, is below and above a critical flux, FX,crit, which may be regulated by ADAF and disk-corona respectively. We find that the data points with anti-correlation of Γ-F3–9keV follow the universal radio–X-ray correlation of FR ∝ FXb (b ~ 0.5-0.7), while the data points with positive X-ray spectral evolution follow a steeper radio–X-ray correlation (b ~ 1.4, the so-called ‘outliers track’). The bright active galactic nuclei (AGNs) share similar X-ray spectral evolution and radio–X-ray correlation as XRBs in ‘outliers’ track, and we present a new fundamental plane of log LR=1.59+0.28−0.22 log LX−0.22+0.19−0.20 log MBH−28.97+0.45−0.45 for these radiatively efficient BH sources.

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