scholarly journals Exploring black hole scaling relations via the ensemble variability of Active Galactic Nuclei

2021 ◽  
Author(s):  
A Georgakakis ◽  
I Papadakis ◽  
M Paolillo
Keyword(s):  
Black Hole ◽  
Galactic Nuclei ◽  
Stellar Mass ◽  
Mass Relation ◽  
Black Hole Mass ◽  
X Ray ◽  
Mass Scaling ◽  
Spectrum Density ◽  
First Time ◽  
Black Hole Masses

Abstract An empirical model is presented that links, for the first time, the demographics of AGN to their ensemble X-ray variability properties. Observations on the incidence of AGN in galaxies are combined with (i) models of the Power Spectrum Density (PSD) of the flux variations of AGN and (ii) parameterisations of the black hole mass versus stellar-mass scaling relation, to predict the mean excess variance of active black hole populations in cosmological volumes. We show that the comparison of the model with observational measurements of the ensemble excess variance as a function of X-ray luminosity provides a handle on both the PSD models and the black hole mass versus stellar mass relation. We find strong evidence against a PSD model that is described by a broken power-law and a constant overall normalization. Instead our analysis indicates that the amplitude of the PSD depends on the physical properties of the accretion events, such as the Eddington ratio and/or the black hole mass. We also find that current observational measurements of the ensemble excess variance are consistent with the black hole mass versus stellar mass relation of local spheroids based on dynamically determined black hole masses. We also discuss future prospects of the proposed approach to jointly constrain the PSD of AGN and the black hole mass versus stellar mass relation as a function of redshift.

scholarly journals On the relationship between black hole mass and X-ray variability amplitude in the low-mass regime of active galactic nuclei

2014 ◽  
Vol 10 (S312) ◽  
pp. 73-74
Author(s):  
H. Pan ◽  
W. Yuan ◽  
X.-L. Zhou ◽  
X. Dong ◽  
B. Liu
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Power Spectrum Density ◽  
Black Hole Mass ◽  
X Ray ◽  
Spectrum Density ◽  
Simple Extrapolation ◽  
Low Mass ◽  
The Relationship

AbstractRecent studies of active galactic nuclei (AGN) found a statistical inverse scaling between the X-ray normalized excess variance σrms2 (variability amplitude) and the black hole mass spanning over MBH = 106 − 109M⊙. We present a study of this relation by including AGN with MBH = 105 − 106M⊙. It is found that the relation is no longer a simple extrapolation of the known inverse proportion, but starts to flatten around 106M⊙. This behavior can be understood by the shape of the power spectrum density of AGN and its dependence on the black hole mass.

Substructure in black hole scaling diagrams and implications for the coevolution of black holes and galaxies

2019 ◽  
Vol 15 (S359) ◽  
pp. 37-39
Author(s):  
Benjamin L. Davis ◽  
Nandini Sahu ◽  
Alister W. Graham
Keyword(s):  
Black Hole ◽  
Stellar Mass ◽  
Host Galaxy ◽  
Scaling Relations ◽  
Black Hole Mass ◽  
Physical Processes ◽  
Stellar Velocity ◽  
Galaxy Sample ◽  
Evolutionary Paths ◽  
Black Hole Masses

AbstractOur multi-component photometric decomposition of the largest galaxy sample to date with dynamically-measured black hole masses nearly doubles the number of such galaxies. We have discovered substantially modified scaling relations between the black hole mass and the host galaxy properties, including the spheroid (bulge) stellar mass, the total galaxy stellar mass, and the central stellar velocity dispersion. These refinements partly arose because we were able to explore the scaling relations for various sub-populations of galaxies built by different physical processes, as traced by the presence of a disk, early-type versus late-type galaxies, or a Sérsic versus core-Sérsic spheroid light profile. The new relations appear fundamentally linked with the evolutionary paths followed by galaxies, and they have ramifications for simulations and formation theories involving both quenching and accretion.

Central Black Hole Masses in Active Galactic Nuclei Inferred from X‐Ray Variability

1998 ◽  
Vol 500 (2) ◽  
pp. 642-659 ◽  
Author(s):  
Kiyoshi Hayashida ◽  
Sigenori Miyamoto ◽  
Shunji Kitamoto ◽  
Hitoshi Negoro ◽  
Hajime Inoue
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Central Black Hole ◽  
X Ray ◽  
Black Hole Masses

scholarly journals Probing black hole accretion tracks, scaling relations, and radiative efficiencies from stacked X-ray active galactic nuclei

2019 ◽  
Vol 493 (1) ◽  
pp. 1500-1511 ◽  
Author(s):  
Francesco Shankar ◽  
David H Weinberg ◽  
Christopher Marsden ◽  
Philip J Grylls ◽  
Mariangela Bernardi ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Selection Bias ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
Independent Evidence ◽  
X Ray ◽  
Black Hole Accretion ◽  
Black Hole Masses ◽  
Hole Accretion

ABSTRACT The masses of supermassive black holes at the centres of local galaxies appear to be tightly correlated with the mass and velocity dispersions of their galactic hosts. However, the local Mbh–Mstar relation inferred from dynamically measured inactive black holes is up to an order-of-magnitude higher than some estimates from active black holes, and recent work suggests that this discrepancy arises from selection bias on the sample of dynamical black hole mass measurements. In this work, we combine X-ray measurements of the mean black hole accretion luminosity as a function of stellar mass and redshift with empirical models of galaxy stellar mass growth, integrating over time to predict the evolving Mbh–Mstar relation. The implied relation is nearly independent of redshift, indicating that stellar and black hole masses grow, on average, at similar rates. Matching the de-biased local Mbh–Mstar relation requires a mean radiative efficiency ε ≳ 0.15, in line with theoretical expectations for accretion on to spinning black holes. However, matching the ‘raw’ observed relation for inactive black holes requires ε ∼ 0.02, far below theoretical expectations. This result provides independent evidence for selection bias in dynamically estimated black hole masses, a conclusion that is robust to uncertainties in bolometric corrections, obscured active black hole fractions, and kinetic accretion efficiency. For our fiducial assumptions, they favour moderate-to-rapid spins of typical supermassive black holes, to achieve ε ∼ 0.12–0.20. Our approach has similarities to the classic Soltan analysis, but by using galaxy-based data instead of integrated quantities we are able to focus on regimes where observational uncertainties are minimized.

scholarly journals X-ray fluctuation timescale and Black Hole mass relation in AGN

2016 ◽  
Vol 12 (S324) ◽  
pp. 172-175
Author(s):  
Amri Wandel ◽  
Mathew Malkan
Keyword(s):  
Black Hole ◽  
Characteristic Time Scale ◽  
Mass Relation ◽  
Black Hole Mass ◽  
Central Black Hole ◽  
X Ray ◽  
Reverberation Mapping ◽  
Power Spectral ◽  
Break Time ◽  
The Time Domain

AbstractWe analyze the fluctuations in the X-ray flux of 20 AGN (mainly Seyfert 1 galaxies) monitored by RXTE and XMM-Newton with a sampling frequency ranging from hours to years, using structure function (SF) analysis. We derive SFs over four orders of magnitude in the time domain (0.03-300 days). Most objects show a characteristic time scale, where the SF flattens or changes slope. For 10 objects with published power-spectral density (PSD) the break time scales in the SF and PSD are similar and show a good correlation. We also find a significant correlation between the SF timescale and the mass of the central black hole, determined for most objects by reverberation mapping.

scholarly journals X-ray variability of 104 active galactic nuclei

2012 ◽  
Vol 8 (S290) ◽  
pp. 37-40
Author(s):  
O. González-Martín ◽  
S. Vaughan
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Power Law ◽  
Galactic Nuclei ◽  
Power Law Model ◽  
Black Hole Mass ◽  
Periodic Oscillations ◽  
Fundamental Plane ◽  
X Ray ◽  
Single Power

AbstractWe have performed a uniform analysis of the power spectrum densities (PSDs) of 104 nearby (z<0.4) active galactic nuclei (AGN) using 209 XMM-Newton/pn observations, including several AGN classes. These PSDs span ≃ 3 decades in temporal frequencies, ranging from minutes to days. We have fitted each PSD to two models: (1) a single power-law model and (2) a bending power-law model. A fraction of 72% show significant variability. The PSD of the majority of the variable AGN was well described by a simple power-law with a mean index of α = 2.01±0.01. In 15 sources we found that the bending power law model was preferred with a mean slope of α = 3.08±0.04 and a mean bend frequency of 〈νb〉 ≃ 2 × 10−4 Hz. Only KUG 1031+398 (RE J1034+396) shows evidence for quasi-periodic oscillations. The ‘fundamental plane’ relating variability timescale, black hole mass, and luminosity is demonstrated using the new X-ray timing results presented here together with a compilation of the previously detected timescales from the literature.

scholarly journals ON THE BLACK HOLE MASS—X-RAY EXCESS VARIANCE SCALING RELATION FOR ACTIVE GALACTIC NUCLEI IN THE LOW-MASS REGIME

2015 ◽  
Vol 808 (2) ◽  
pp. 163 ◽  
Author(s):  
Hai-Wu Pan ◽  
Weimin Yuan ◽  
Xin-Lin Zhou ◽  
Xiao-Bo Dong ◽  
Bifang Liu
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Scaling Relation ◽  
Black Hole Mass ◽  
X Ray ◽  
Low Mass
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