Massive black hole binaries in active galactic nuclei

Nature ◽  
1980 ◽  
Vol 287 (5780) ◽  
pp. 307-309 ◽  
Author(s):  
M. C. Begelman ◽  
R. D. Blandford ◽  
M. J. Rees
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Massive Black Hole ◽  
Black Hole Binaries

scholarly journals Variabiity of the X-ray broad iron spectral features in active galactic nuclei and black-hole binaries

2016 ◽  
Vol 337 (4-5) ◽  
pp. 507-511
Author(s):  
M. Mizumoto ◽  
K. Ebisawa ◽  
M. Tsujimoto ◽  
H. Inoue
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Spectral Features ◽  
X Ray ◽  
Black Hole Binaries

The Starburst-AGN Connection: 3-D Structure of the Massive Gas Disk around the Nucleus

2003 ◽  
Vol 208 ◽  
pp. 463-464
Author(s):  
Keiichi Wada ◽  
Colin A. Norman
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Interstellar Matter ◽  
Viewing Angle ◽  
Massive Black Hole ◽  
Hydrodynamical Simulations ◽  
Multi Phase ◽  
Globally Stable ◽  
High Column

The structure of obscuring matter in the environment of active galactic nuclei with associated nuclear starbursts is investigated using 3-D hydrodynamical simulations, in which the multi-phase inhomogeneous interstellar matter and its interaction with the supernovae are consistently followed. A globally stable, torus-like, but highly inhomogeneous and turbulent structure is found. To achieve the high column densities as suggested by observations of some Seyfert 2 galaxies with nuclear starbursts, the viewing angle should be larger than about 70° from the pole-on for a 108M⊙ massive black hole. We propose that nuclear starbursts and the mass of the black hole that determines the geometry of the obscuring torus.

scholarly journals Post-Newtonian simulations of super-massive black hole binaries in galactic nuclei

2008 ◽  
Vol 329 (9-10) ◽  
pp. 904-907 ◽  
Author(s):  
I. Berentzen ◽  
M. Preto ◽  
P. Berczik ◽  
D. Merritt ◽  
R. Spurzem
Keyword(s):  
Black Hole ◽  
Galactic Nuclei ◽  
Massive Black Hole ◽  
Black Hole Binaries

scholarly journals Spin Evolution of Stellar-mass Black Hole Binaries in Active Galactic Nuclei

2020 ◽  
Vol 899 (1) ◽  
pp. 26 ◽  
Author(s):  
Hiromichi Tagawa ◽  
Zoltán Haiman ◽  
Imre Bartos ◽  
Bence Kocsis
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Stellar Mass ◽  
Black Hole Binaries ◽  
Spin Evolution

scholarly journals Active Galactic Nuclei: Variability at Many Wavelengths

1998 ◽  
Vol 11 (2) ◽  
pp. 808-811
Author(s):  
Thierry J.-L. Courvoisier
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Thermal Emission ◽  
Galactic Nuclei ◽  
Gravitational Energy ◽  
Heating Process ◽  
Massive Black Hole ◽  
Ultraviolet Emission ◽  
X Ray ◽  
Accretion Process

Active Galactic Nuclei (AGN) are thought to be powered by accretion onto a massive black hole. Understanding how gravitational energy freed by the infall of matter into the black hole is transferred to the radiating regions of the nucleus is one of the main challenges of AGN research. The question is made very complex by the presence of several cooling mechanisms with very diverse physical properties: We observe synchrotron radiation, thermal emission from hot dust, possibly thermal optical and ultraviolet emission and Comptonization processes in the X-ray domain. For each component the radiation is a signature of the cooling process rather than of the heating process. It is our hope that by observing the links and correlations between the emission of the different components we will be able to understand how they are interrelated and how they get their energy supply from the accretion process.

scholarly journals Black Hole Models of Quasars

1986 ◽  
Vol 119 ◽  
pp. 359-369 ◽  
Author(s):  
R. D. Blandford
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Cosmic Time ◽  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
Massive Black Hole ◽  
Binary Black Holes ◽  
Electron Positron ◽  
Gas Supply

Observations of active galactic nuclei are interpreted in terms of a theoretical model involving accretion onto a massive black hole. Optical quasars and Seyfert galaxies are associated with holes accreting near the Eddington rate and radio galaxies with sub-critical accretion. It is argued that magnetic fields are largely responsible for extracting energy and angular momentum from black holes and disks. Recent studies of electron-positron pair plasmas and their possible role in establishing the emergent X-ray spectrum are reviewed. The main evolutionary properties of active galactic nuclei can be interpreted in terms of a simple model in which black holes accrete gas at a rate dictated by the rate of gas supply which decreases with cosmic time. It may be worth searching for eclipsing binary black holes in lower power Seyferts.

scholarly journals A search for H2O masers in 100 active dwarf galaxies

2020 ◽  
Vol 499 (1) ◽  
pp. 1233-1249
Author(s):  
M J Rosenthal ◽  
I Zaw
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Detection Rate ◽  
Dwarf Galaxies ◽  
Galactic Nuclei ◽  
Optical Emission ◽  
Massive Black Hole ◽  
Massive Galaxies ◽  
Low Mass ◽  
Green Bank Telescope

ABSTRACT We present the results of the first dedicated survey for 22 GHz H2O maser emission in dwarf galaxies outside of the Local Group, with the aim of discovering disc masers. Studies of disc masers yield accurate and precise measurements of black hole (BH) mass, and such measurements in dwarf galaxies would be key to understanding the low-mass end of BH–galaxy coevolution. We used the Green Bank Telescope to survey 100 nearby (z ≲ 0.055) dwarf galaxies (M* ≲ 109.5 M⊙) with optical emission line ratios indicative of accretion on to a massive black hole. We detected no new masers down to a limit of ∼12 mJy (5σ). We compared the properties of our sample with those of ∼1850 known detections and non-detections in massive galaxies. We find, in agreement with previous studies, that masers are preferentially hosted by Seyferts and highly obscured, [O iii]-bright active galactic nuclei (AGNs). Our sample has fewer Seyferts, is less obscured, and is [O iii]-faint. Though the overall maser detection rate is ∼3 per cent in massive galaxies, the predicted rate for our sample, weighted by its optical properties, is ∼0.6–1.7 per cent, corresponding to a probability of making no detections of ∼20–50 per cent. We also found a slight increase in the detection rate with increased stellar mass in previously surveyed galaxies. However, further observations are required to discern whether there is an intrinsic difference between the maser fraction in active dwarf galaxies and in their massive counterparts for the same AGN properties.

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