Epicyclic Oscillations around Simpson–Visser Regular Black Holes and Wormholes

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.

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Supermassive black holes surrounded by dark matter modeled as anisotropic fluid: epicyclic oscillations and their fitting to observed QPOs

Journal of Cosmology and Astroparticle Physics ◽

10.1088/1475-7516/2021/11/059 ◽

2021 ◽

Vol 2021 (11) ◽

pp. 059

Author(s):

Z. Stuchlík ◽

J. Vrba

Keyword(s):

Black Holes ◽

Black Hole ◽

Dark Matter ◽

Active Galactic Nuclei ◽

Galactic Nuclei ◽

Supermassive Black Holes ◽

Anisotropic Fluid ◽

Physical Parameters ◽

Black Hole Spacetimes ◽

Test Particles

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.

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Epicyclic oscillations in spinning particle motion around Kerr black hole applied in models fitting the quasi-periodic oscillations observed in microquasars and AGNs

The European Physical Journal C ◽

10.1140/epjc/s10052-021-09868-1 ◽

2021 ◽

Vol 81 (12) ◽

Author(s):

Misbah Shahzadi ◽

Martin Kološ ◽

Zdeněk Stuchlík ◽

Yousaf Habib

Keyword(s):

Black Hole ◽

Active Galactic Nuclei ◽

High Frequency ◽

Kerr Black Hole ◽

Galactic Nuclei ◽

Tidal Disruption ◽

Periodic Oscillations ◽

Spinning Particle ◽

X Ray ◽

Test Particles

AbstractThe study of the quasi-periodic oscillations (QPOs) of X-ray flux observed in the stellar-mass black hole (BH) binaries or quasars can provide a powerful tool for testing the phenomena occurring in strong gravity regime. We thus fit the data of QPOs observed in the well known microquasars as well as active galactic nuclei (AGNs) in the framework of the model of geodesic oscillations of Keplerian disks modified for the epicyclic oscillations of spinning test particles orbiting Kerr BHs. We show that the modified geodesic models of QPOs can explain the observational fixed data from the microquasars and AGNs but not for all sources. We perform a successful fitting of the high frequency QPOs models of epicyclic resonance and its variants, relativistic precession and its variants, tidal disruption, as well as warped disc models, and discuss the corresponding constraints of parameters of the model, which are the spin of the test particle, mass and rotation of the BH.

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Determination of supermassive black hole spins in active galactic nuclei

International Journal of Modern Physics A ◽

10.1142/s0217751x20400540 ◽

2020 ◽

Vol 35 (02n03) ◽

pp. 2040054

Author(s):

M. Yu. Piotrovich ◽

V. L. Afanasiev ◽

S. D. Buliga ◽

T. M. Natsvlishvili

Keyword(s):

Black Holes ◽

Black Hole ◽

Active Galactic Nuclei ◽

Accretion Disk ◽

Galactic Nuclei ◽

Supermassive Black Holes ◽

Disk Model ◽

Supermassive Black Hole

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.

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Supermassive Black Holes in Active Galactic Nuclei. I. The Consistency of Black Hole Masses in Quiescent and Active Galaxies

The Astrophysical Journal ◽

10.1086/322528 ◽

2001 ◽

Vol 555 (2) ◽

pp. L79-L82 ◽

Cited By ~ 243

Author(s):

Laura Ferrarese ◽

Richard W. Pogge ◽

Bradley M. Peterson ◽

David Merritt ◽

Amri Wandel ◽

...

Keyword(s):

Black Holes ◽

Black Hole ◽

Active Galactic Nuclei ◽

Galactic Nuclei ◽

Supermassive Black Holes ◽

Active Galaxies ◽

Black Hole Masses

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

The Astrophysical Journal ◽

10.1086/424655 ◽

2004 ◽

Vol 615 (2) ◽

pp. 645-651 ◽

Cited By ~ 440

Author(s):

Christopher A. Onken ◽

Laura Ferrarese ◽

David Merritt ◽

Bradley M. Peterson ◽

Richard W. Pogge ◽

...

Keyword(s):

Black Holes ◽

Black Hole ◽

Active Galactic Nuclei ◽

Mass Velocity ◽

Velocity Dispersion ◽

Galactic Nuclei ◽

Supermassive Black Holes ◽

Black Hole Mass ◽

Dispersion Relationship

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Possible Wormhole Candidates in Active Galactic Nuclei

Universe ◽

10.3390/universe6080120 ◽

2020 ◽

Vol 6 (8) ◽

pp. 120

Author(s):

Mikhail Piotrovich ◽

Serguei Krasnikov ◽

Stanislava Buliga ◽

Tinatin Natsvlishvili

Keyword(s):

Black Holes ◽

Gamma Radiation ◽

Physical Properties ◽

Active Galactic Nuclei ◽

Observational Data ◽

Galactic Nuclei ◽

Supermassive Black Holes ◽

Radiative Efficiency ◽

Characteristic Spectrum ◽

The Difference

The hypothesis is considered that the active galactic nuclei (AGNs) are wormhole (WH) mouths rather than supermassive black holes (SMBHs). We study the difference in the physical properties of such objects from those of AGNs with SMBH, as well as the the corresponding difference in observational data. Firstly, the radiative efficiency for some types of WHs (both static and rotating) can be significantly larger than the theoretical maximal value for the Kerr SMBHs. A number of AGNs is presented, for which the observational data can be interpreted as the result of the presence of WHs in them. Secondly, a sufficiently strong gamma radiation with a characteristic spectrum noticeably differing from that of AGNs jets, can be emitted from a static WH as a result of a collision of accreting flows of matter inside the WH.

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Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. VIII. Structure of the Broad-line Region and Mass of the Central Black Hole in Mrk 142

The Astrophysical Journal ◽

10.3847/1538-4357/aaee6b ◽

2018 ◽

Vol 869 (2) ◽

pp. 137 ◽

Cited By ~ 23

Author(s):

Yan-Rong Li ◽

Yu-Yang Songsheng ◽

Jie Qiu ◽

Chen Hu ◽

Pu Du ◽

...

Keyword(s):

Black Holes ◽

Black Hole ◽

Active Galactic Nuclei ◽

Galactic Nuclei ◽

Supermassive Black Holes ◽

Broad Line ◽

Central Black Hole ◽

Broad Line Region ◽

Line Region ◽

Accretion Rates

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The ecology of the galactic centre: Nuclear stellar clusters and supermassive black holes

Proceedings of the International Astronomical Union ◽

10.1017/s1743921319006689 ◽

2019 ◽

Vol 14 (S351) ◽

pp. 80-83 ◽

Cited By ~ 1

Author(s):

Melvyn B. Davies ◽

Abbas Askar ◽

Ross P. Church

Keyword(s):

Black Holes ◽

Black Hole ◽

Large Fraction ◽

Galactic Nuclei ◽

Supermassive Black Holes ◽

Galactic Centre ◽

Stellar Clusters ◽

Stellar Cluster ◽

Supermassive Black Hole ◽

Multiple Clusters

AbstractSupermassive black holes are found in most galactic nuclei. A large fraction of these nuclei also contain a nuclear stellar cluster surrounding the black hole. Here we consider the idea that the nuclear stellar cluster formed first and that the supermassive black hole grew later. In particular we consider the merger of three stellar clusters to form a nuclear stellar cluster, where some of these clusters contain a single intermediate-mass black hole (IMBH). In the cases where multiple clusters contain IMBHs, we discuss whether the black holes are likely to merge and whether such mergers are likely to result in the ejection of the merged black hole from the nuclear stellar cluster. In some cases, no supermassive black hole will form as any merger product is not retained. This is a natural pathway to explain those galactic nuclei that contain a nuclear stellar cluster but apparently lack a supermassive black hole; M33 being a nearby example. Alternatively, if an IMBH merger product is retained within the nuclear stellar cluster, it may subsequently grow, e.g. via the tidal disruption of stars, to form a supermassive black hole.

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Symmetry and the Arrow of Time in Theoretical Black Hole Astrophysics

Journal of Gravity ◽

10.1155/2015/530850 ◽

2015 ◽

Vol 2015 ◽

pp. 1-5

Author(s):

David Garofalo

Keyword(s):

Black Holes ◽

Black Hole ◽

Active Galactic Nuclei ◽

Accretion Disks ◽

Time Reversal ◽

Large Scale ◽

Galactic Nuclei ◽

Arrow Of Time ◽

Time Symmetry ◽

The Universe

While the basic laws of physics seem time-reversal invariant, our understanding of the apparent irreversibility of the macroscopic world is well grounded in the notion of entropy. Because astrophysics deals with the largest structures in the Universe, one expects evidence there for the most pronounced entropic arrow of time. However, in recent theoretical astrophysics work it appears possible to identify constructs with time-reversal symmetry, which is puzzling in the large-scale realm especially because it involves the engines of powerful outflows in active galactic nuclei which deal with macroscopic constituents such as accretion disks, magnetic fields, and black holes. Nonetheless, the underlying theoretical structure from which this accreting black hole framework emerges displays a time-symmetric harmonic behavior, a feature reminiscent of basic and simple laws of physics. While we may expect such behavior for classical black holes due to their simplicity, manifestations of such symmetry on the scale of galaxies, instead, surprise. In fact, we identify a parallel between the astrophysical tug-of-war between accretion disks and jets in this model and the time symmetry-breaking of a simple overdamped harmonic oscillator. The validity of these theoretical ideas in combination with this unexpected parallel suggests that black holes are more influential in astrophysics than currently recognized and that black hole astrophysics is a more fundamental discipline.

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