scholarly journals X-ray properties of reverberation-mapped AGNs with super-Eddington accreting massive black holes

2019 ◽  
Vol 15 (S356) ◽  
pp. 143-143
Author(s):  
Jaya Maithil ◽  
Michael S. Brotherton ◽  
Bin Luo ◽  
Ohad Shemmer ◽  
Sarah C. Gallagher ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Accretion Rate ◽  
Time Lags ◽  
Black Hole Mass ◽  
Host Galaxies ◽  
Massive Black Holes ◽  
X Ray ◽  
Photon Index ◽  
The Impact

AbstractActive Galactic Nuclei (AGN) exhibit multi-wavelength properties that are representative of the underlying physical processes taking place in the vicinity of the accreting supermassive black hole. The black hole mass and the accretion rate are fundamental for understanding the growth of black holes, their evolution, and the impact on the host galaxies. Recent results on reverberation-mapped AGNs show that the highest accretion rate objects have systematic shorter time-lags. These super-Eddington accreting massive black holes (SEAMBHs) show BLR size 3-8 times smaller than predicted by the Radius-Luminosity (R-L) relationship. Hence, the single-epoch virial black hole mass estimates of highly accreting AGNs have an overestimation of a factor of 3-8 times. SEAMBHs likely have a slim accretion disk rather than a thin disk that is diagnostic in X-ray. I will present the extreme X-ray properties of a sample of dozen of SEAMBHs. They indeed have a steep hard X-ray photon index, Γ, and demonstrate a steeper power-law slope, ασx.

scholarly journals Black hole mass accretion rates and efficiency factors for over 750 AGN and multiple GBH

2020 ◽  
Vol 500 (1) ◽  
pp. 215-231
Author(s):  
Ruth A Daly
Keyword(s):  
Black Hole ◽  
Radio Emission ◽  
Binary Systems ◽  
Accretion Rate ◽  
Beam Power ◽  
Black Hole Mass ◽  
X Ray ◽  
Accretion Rates ◽  
Efficiency Factors ◽  
The Impact

ABSTRACT Mass accretion rates in dimensionless and physical units, and efficiency factors describing the total radiant luminosity of the disc and the beam power of the outflow are obtained and studied here for samples of black hole systems with outflows. Four samples of sources including 576 LINERs, 100 classical double (FRII) radio sources, 80 relatively local AGN, and 103 measurements of four stellar mass X-ray binary systems, referred to as Galactic Black Holes (GBHs), are included in the study. All of the sources have highly collimated outflows leading to compact radio emission or powerful extended (FRII) radio emission. The properties of each of the full samples are explored, as are those of the four individual GBH, and sub-types of the FRII and local AGN samples. Source types and sub-types that have high, medium, and low values of accretion rates and efficiency factors are identified and studied. A new efficiency factor that describes the relative impact of black hole spin and mass accretion rate on the beam power is defined and studied, and is found to provide a new and interesting diagnostic. Mass accretion rates for 13 sources and efficiency factors for 6 sources are compared with values obtained independently, and indicate that similar values are obtained with independent methods. The mass accretion rates and efficiency factors obtained here substantially increase the number of values available, and improve our understanding of their relationship to source types. The redshift dependence of quantities is presented and the impact on the results is discussed.

scholarly journals The soft X-ray excess: NLS1s versus BLS1s

2019 ◽  
Vol 491 (1) ◽  
pp. 532-543 ◽  
Author(s):  
Mario Gliozzi ◽  
James K Williams
Keyword(s):  
Black Hole ◽  
Accretion Rate ◽  
Galactic Nuclei ◽  
X Rays ◽  
Black Hole Mass ◽  
X Ray ◽  
Two Samples ◽  
Photon Index ◽  
Model Independent

ABSTRACT The soft X-ray excess – the excess of X-rays below 2 keV with respect to the extrapolation of the hard X-ray spectral continuum model – is a very common feature among type 1 active galactic nuclei (AGNs); yet the nature of the soft X-ray excess is still poorly understood and hotly debated. To shed some light on this issue, we have measured in a model-independent way the soft excess strength in a flux-limited sample of broad- and narrow-line Seyfert 1 galaxies (BLS1s and NLS1s) that are matched in X-ray luminosity but different in terms of the black hole mass and the accretion rate values, with NLS1s being characterized by smaller MBH and larger $\dot{m}$ values. Our analysis, in agreement with previous studies carried out with different AGN samples, indicates that: (1) a soft excess is ubiquitously detected in both BLS1s and NLS1s; (2) the strength of the soft excess is significantly larger in the NLS1 sample, compared to the BLS1 sample; and (3) combining the two samples, the strength of the soft excess appears to positively correlate with the photon index as well as with the accretion rate, whereas there is no correlation with the black hole mass. Importantly, our work also reveals the lack of an anticorrelation between the soft excess strength and the luminosity of the primary X-ray component, predicted by the absorption and reflection scenarios. Our findings suggest that the soft excess is consistent with being produced by a warm Comptonization component. Larger, more complete samples of NLS1s and BLS1s are needed to confirm these conclusions.

scholarly journals The Sub-Eddington Boundary for the Quasar Mass–Luminosity Plane: A Theoretical Perspective

Universe ◽  
2019 ◽  
Vol 5 (6) ◽  
pp. 145 ◽  
Author(s):  
David Garofalo ◽  
Damian J. Christian ◽  
Andrew M. Jones
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Survey Data ◽  
Theoretical Perspective ◽  
Sloan Digital Sky Survey ◽  
Black Hole Mass ◽  
Massive Black Holes ◽  
Sky Survey ◽  
Data Release ◽  
Gap Paradigm

By exploring more than sixty thousand quasars from the Sloan Digital Sky Survey Data Release 5, Steinhardt & Elvis discovered a sub-Eddington boundary and a redshift-dependent drop-off at higher black hole mass, possible clues to the growth history of massive black holes. Our contribution to this special issue of Universe amounts to an application of a model for black hole accretion and jet formation to these observations. For illustrative purposes, we include ~100,000 data points from the Sloan Digital Sky Survey Data Release 7 where the sub-Eddington boundary is also visible and propose a theoretical picture that explains these features. By appealing to thin disk theory and both the lower accretion efficiency and the time evolution of jetted quasars compared to non-jetted quasars in our “gap paradigm”, we explain two features of the sub-Eddington boundary. First, we show that a drop-off on the quasar mass-luminosity plane for larger black hole mass occurs at all redshifts. But the fraction of jetted quasars is directly related to the merger function in this paradigm, which means the jetted quasar fraction drops with decrease in redshift, which allows us to explain a second feature of the sub-Eddington boundary, namely a redshift dependence of the slope of the quasar mass–luminosity boundary at high black hole mass stemming from a change in radiative efficiency with time. We are able to reproduce the mass dependence of, as well as the oscillating behavior in, the slope of the sub-Eddington boundary as a function of time. The basic physical idea involves retrograde accretion occurring only for a subset of the more massive black holes, which implies that most spinning black holes in our model are prograde accretors. In short, this paper amounts to a qualitative overview of how a sub-Eddington boundary naturally emerges in the gap paradigm.

scholarly journals AGN radiative feedback in the early growth of massive black holes

2019 ◽  
Vol 489 (4) ◽  
pp. 5225-5230
Author(s):  
W Ishibashi
Keyword(s):  
Black Holes ◽  
Early Universe ◽  
Radiation Pressure ◽  
Early Growth ◽  
Host Galaxies ◽  
Massive Black Holes ◽  
Black Hole Growth ◽  
Hole Growth ◽  
The Impact ◽  
Very High

ABSTRACT Growing observational evidence confirms the existence of massive black holes ($M_{\rm BH} \sim 10^9 \, \mathrm{M}_{\odot }$), accreting at rates close to the Eddington limit, at very high redshifts ($z \gtrsim 6\!-\!7$) in the early Universe. Recent observations indicate that the host galaxies of the first quasars are chemically evolved systems, containing unexpectedly large amounts of dust. Such a combination of high luminosities and large dust content should form favourable physical conditions for radiative dusty feedback. We explore the impact of the active galactic nucleus (AGN) feedback, driven by radiation pressure on dust, on the early growth of massive black holes. Assuming Eddington-limited exponential black hole growth, we find that the dynamics and energetics of the radiation pressure-driven outflows also follow exponential trends at late times. We obtain modest outflow energetics (with momentum flux $\dot{p} \lesssim L/c$ and kinetic power $\dot{E}_{\rm k} \lesssim 10^{-3} L$), comparable with available observations of quasar-driven outflows at very high redshifts, but significantly lower than typically observed in local quasars and predicted by wind energy-driven models. AGN radiative dusty feedback may thus play an important role in powering galactic outflows in the first quasars in the early Universe.

Density diagnostics of photoionized outflows in active galactic nuclei

2019 ◽  
Vol 15 (S350) ◽  
pp. 274-277
Author(s):  
Junjie Mao
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
State Of The Art ◽  
Density Measurement ◽  
Galactic Nuclei ◽  
Next Generation ◽  
Host Galaxies ◽  
Current Generation ◽  
X Ray ◽  
The Impact

AbstractPhotoionized outflows in active galactic nuclei (AGNs) are thought to influence their circumnuclear and host galactic environment. However, the distance of the outflow with respect to the black hole is poorly constrained, which limits our understanding of the kinetic power by the outflow. Therefore, the impact of AGN outflows on their host galaxies is uncertain. If the density of the outflow is known, its distance can be derived. Density measurement via variability studies and density sensitive lines have been used, albeit not very effective in the X-ray band. Good measurements are rather demanding or challenging for the current generation of (grating) spectrometers. The next generation of spectrometers will certainly provide data with better quality and large quantity, leading to tight constraints on the location and the kinetic power of AGN outflows. This contribution summarizes the state-of-the-art in this field.

scholarly journals Matter accretion onto a conformal gravity black hole

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
G. Abbas ◽  
A. Ditta
Keyword(s):  
Black Hole ◽  
Equations Of State ◽  
Accretion Rate ◽  
Black Hole Mass ◽  
Conformal Gravity ◽  
De Sitter ◽  
Schwarzschild Black Hole ◽  
Mass Rate ◽  
Mass Accretion Rate ◽  
The Impact

AbstractThe accretion of test fluids flowing onto a black hole is investigated. Particularly, by adopting a dynamical Hamiltonian approach, we are capable to find the critical points for various cases of black hole in conformal gravity. In these cases, we have analyzed the general solutions of accretion employing the isothermal equations of state. The steady state and spherically symmetric accretion of different test fluids onto the conformal gravity black hole has been considered. Further, we have classified these flows in the context of equations of state and the cases of conformal gravity black hole. The new behavior of polytropic fluid accretion is also discussed in all three cases of black hole. Black hole mass accretion rate is the most important part of this research in which we have investigated that the Schwarzschild black hole produce a typical signature than the conformal gravity black hole and Schwarzschild–de Sitter black hole. The critical fluid flow and the mass accretion rate have been presented graphically by the impact parameters $$\beta $$ β , $$\gamma $$ γ , k and these parameters have great significance. Additionally, the maximum mass rate of accretion fall near the universal and Killing horizons and minimum rate of accretion occurs in between these regions. Finally, the results are compared with the different cases of black hole available in the literature.

scholarly journals Time lags in the ultraluminous X-ray source NGC 5408 X-1: implications for the black hole mass

2013 ◽  
Vol 436 (4) ◽  
pp. 3782-3791 ◽  
Author(s):  
B. De Marco ◽  
G. Ponti ◽  
G. Miniutti ◽  
T. Belloni ◽  
M. Cappi ◽  
...  
Keyword(s):  
Black Hole ◽  
Time Lags ◽  
Black Hole Mass ◽  
X Ray

scholarly journals Inclination effects on the X-ray emission of Galactic black-hole binaries

2019 ◽  
Vol 625 ◽  
pp. A90 ◽  
Author(s):  
Pablo Reig ◽  
Nikolaos D. Kylafis
Keyword(s):  
Black Hole ◽  
Linear Regression Analysis ◽  
Time Lag ◽  
Light Curves ◽  
Energy Spectra ◽  
Time Lags ◽  
X Ray ◽  
Galactic Black Hole ◽  
Photon Index ◽  
Inclination Angles

Context. Galactic black-hole X-ray binaries (BHBs) emit a compact, optically thick, mildly relativistic radio jet when they are in hard and hard-intermediate states. In these states, BHBs exhibit a correlation between the time lag of hard with respect to softer photons and the photon index of the power law component that characterizes the X-ray spectral continuum above ∼10 keV. The correlation, however, shows large scatter. In recent years, several works have brought to light the importance of taking into account the inclination of the systems to understand the X-ray and radio phenomenology of BHBs. Aims. Our objective is to investigate the role that the inclination plays on the correlation between the time lag and photon index. Methods. We obtained RXTE energy spectra and light curves of a sample of BHBs with different inclination angles. We computed the photon index and the time lag between hard and soft photons and performed a correlation and linear regression analysis of the two variables. We also computed energy spectra and light curves of BHBs using the Monte Carlo technique that reproduces the process of Comptonization in the jet. We account for the inclination effects by recording the photons that escape from the jet at different angles. From the simulated light curves and spectra we obtained model-dependent photon index and time lags, which we compared with those obtained from the real data. Results. We find that the correlation between the time lag and photon index is tight in low-inclination systems and becomes weaker in high-inclination systems. The amplitude of the lags is also larger at low- and intermediate-inclination angles than at high inclination. We also find that the photon index and time lag, obtained from the simulated spectra and light curves, also follow different relationships for different inclination angle ranges. Our jet model reproduces the observations remarkably well. The same set of models that reproduces the correlation for the low-inclination systems, also accounts for the correlation for intermediate- and high-inclination systems fairly well. Conclusions. The large dispersion observed in the time lag – photon index correlation in BHBs can naturally be explained as an inclination effect. Comptonization in the jet explains the steeper dependence of the lags on the photon index in low- and intermediate-inclination systems than in high-inclination systems.

scholarly journals Radio and X-ray detections of GX 339–4 in quiescence using MeerKAT and Swift

2020 ◽  
Vol 493 (1) ◽  
pp. L132-L137 ◽  
Author(s):  
E Tremou ◽  
S Corbel ◽  
R P Fender ◽  
P A Woudt ◽  
J C A Miller-Jones ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Binary Systems ◽  
Accretion Rate ◽  
Galactic Nuclei ◽  
Stellar Mass ◽  
X Ray ◽  
Accretion Process ◽  
Upper Limits

ABSTRACT The radio–X-ray correlation that characterizes accreting black holes at all mass scales – from stellar mass black holes in binary systems to supermassive black holes powering active galactic nuclei – is one of the most important pieces of observational evidence supporting the existence of a connection between the accretion process and the generation of collimated outflows – or jets – in accreting systems. Although recent studies suggest that the correlation extends down to low luminosities, only a handful of stellar mass black holes have been clearly detected, and in general only upper limits (especially at radio wavelengths) can be obtained during quiescence. We recently obtained detections of the black hole X-ray binary (XRB) GX 339–4 in quiescence using the Meer Karoo Array Telescope (MeerKAT) radio telescope and Swift X-ray Telescope instrument on board the Neil Gehrels Swift Observatory, probing the lower end of the radio–X-ray correlation. We present the properties of accretion and of the connected generation of jets in the poorly studied low-accretion rate regime for this canonical black hole XRB system.

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