scholarly journals Supermassive Black Holes in Active Galactic Nuclei. II. Calibration of the Black Hole Mass–Velocity Dispersion Relationship for Active Galactic Nuclei

2004 ◽  
Vol 615 (2) ◽  
pp. 645-651 ◽  
Author(s):  
Christopher A. Onken ◽  
Laura Ferrarese ◽  
David Merritt ◽  
Bradley M. Peterson ◽  
Richard W. Pogge ◽  
...  
Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 279
Author(s):  
Zdeněk Stuchlík ◽  
Jaroslav Vrba

We study epicyclic oscillatory motion along circular geodesics of the Simpson–Visser meta-geometry describing in a unique way regular black-bounce black holes and reflection-symmetric wormholes by using a length parameter l. We give the frequencies of the orbital and epicyclic motion in a Keplerian disc with inner edge at the innermost circular geodesic located above the black hole outer horizon or on the our side of the wormhole. We use these frequencies in the epicyclic resonance version of the so-called geodesic models of high-frequency quasi-periodic oscillations (HF QPOs) observed in microquasars and around supermassive black holes in active galactic nuclei to test the ability of this meta-geometry to improve the fitting of HF QPOs observational data from the surrounding of supermassive black holes. We demonstrate that this is really possible for wormholes with sufficiently high length parameter l.


2021 ◽  
Vol 2021 (11) ◽  
pp. 059
Author(s):  
Z. Stuchlík ◽  
J. Vrba

Abstract Recently introduced exact solution of the Einstein gravity coupled minimally to an anisotropic fluid representing dark matter can well represent supermassive black holes in galactic nuclei with realistic distribution of dark matter around the black hole, given by the Hernquist-like density distribution. For these fluid-hairy black hole spacetimes, properties of the gravitational radiation, quasinormal ringing, and optical phenomena were studied, giving interesting results. Here, using the range of physical parameters of these spacetimes allowing for their relevance in astrophysics, we study the epicyclic oscillatory motion of test particles in these spacetimes. The frequencies of the orbital and epicyclic motion are applied in the epicyclic resonance variant of the geodesic model of quasiperiodic oscillations (QPOs) observed in active galactic nuclei to demonstrate the possibility to solve the cases where the standard vacuum black hole spacetimes are not allowing for explanation of the observed data. We demonstrate that the geodesic model can explain the QPOs observed in most of the active galactic nuclei for the fluid-hairy black holes with reasonable halo parameters.


2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040054
Author(s):  
M. Yu. Piotrovich ◽  
V. L. Afanasiev ◽  
S. D. Buliga ◽  
T. M. Natsvlishvili

Based on spectropolarimetry for a number of active galactic nuclei in Seyfert 1 type galaxies observed with the 6-m BTA telescope, we have estimated the spins of the supermassive black holes at the centers of these galaxies. We have determined the spins based on the standard Shakura-Sunyaev accretion disk model. More than 70% of the investigated active galactic nuclei are shown to have Kerr supermassive black holes with a dimensionless spin greater than 0.9.


2001 ◽  
Vol 555 (2) ◽  
pp. L79-L82 ◽  
Author(s):  
Laura Ferrarese ◽  
Richard W. Pogge ◽  
Bradley M. Peterson ◽  
David Merritt ◽  
Amri Wandel ◽  
...  

2015 ◽  
Vol 11 (S319) ◽  
pp. 60-60
Author(s):  
Chiaki Kobayashi ◽  
Philip Taylor

AbstractIn our cosmological, chemodynamical simulations, (i) the black hole mass–velocity dispersion relation does not evolve, and black holes actually grow along the relation. (ii) the stellar mass–metallicity relation does not change its shape, while the gas-phase relation has a steeper slope at higher redshifts. (iii) While stellar metallicity gradients are made shallower by galaxy mergers, gas-phase gradients are affected more strongly by AGN feedback.


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