Ratio of the jet power to the bolometric luminosity of the disk during accretion onto a black hole

AbstractIn galactic nuclei (AGN), the kinetic energy flux of the jet may exceed the bolometric luminosity of the disk a few orders of magnitude. At the “cold” accretion the radiation from the disk is suppressed because the wind from the disk carries out almost all the angular momentum and the gravitational energy of the accreted material. We calculate an unavoidable radiation from such a disk and the ratio of the kinetic-to-bolometric luminosity from a super massive black hole in framework of the paradigm of the optically thick α-disk of Shakura & Sunyaev. The results confirm that the gravitational energy of the accreted material can be the only source of energy in AGNs.

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Physics of “Cold” Disk Accretion onto Black Holes Driven by Magnetized Winds

Galaxies ◽

10.3390/galaxies7010018 ◽

2019 ◽

Vol 7 (1) ◽

pp. 18 ◽

Cited By ~ 1

Author(s):

Sergey Bogovalov

Keyword(s):

Black Holes ◽

Black Hole ◽

Angular Momentum ◽

Numerical Solutions ◽

Turbulent Viscosity ◽

Disk Accretion ◽

Massive Black Hole ◽

Bolometric Luminosity ◽

Semi Empirical ◽

Jet Power

Disk accretion onto black holes is accompanied by collimated outflows (jets). In active galactic nuclei (AGN), the kinetic energy flux of the jet (jet power or kinetic luminosity) may exceed the bolometric luminosity of the disk by a few orders of magnitude. This may be explained in the framework of the so called “cold” disk accretion. In this regime of accretion, the disk is radiatively inefficient because practically all the energy released at the accretion is carried out by the magnetized wind. This wind also provides efficient loss of the angular momentum by the matter in the disk. In this review, the physics of the accretion driven by the wind is considered from first principles. It is shown that the magnetized wind can efficiently carry out angular momentum and energy of the matter of the disk. The conditions when this process dominates conventional loss of the angular momentum due to turbulent viscosity are discussed. The “cold” accretion occurs when the viscous stresses in the disk can be neglected in comparison with impact of the wind on the accretion. Two problems crucial for survival of the model of “cold” accretion are considered. The first one is existence of the magnetohydrodynamical solutions for disk accretion purely due to the angular momentum loss by the wind. Another problem is the ability of the model to reproduce observations which demonstrate existence of the sources with kinetic power of jets 2–3 orders of magnitude exceeding the bolometric luminosity of disks. The solutions of the problem in similar prescriptions and numerical solutions without such an assumption are discussed. Calculations of the “unavoidable” radiation from the “cold” disk and the ratio of the jet power of the SMBH to the bolometric luminosity of the accretion disk around a super massive black hole are given in the framework of the Shakura and Sunyaev paradigm of an optically thick α -disk. The exploration of the Fundamental Plane of Black Holes allows us to obtain semi empirical equations that determine the bolometric luminosity and the ratio of the luminosities as functions of the black hole mass and accretion rate.

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Detection of the Schwarzschild precession in the orbit of the star S2 near the Galactic centre massive black hole

Astronomy and Astrophysics ◽

10.1051/0004-6361/202037813 ◽

2020 ◽

Vol 636 ◽

pp. L5 ◽

Cited By ~ 39

Author(s):

◽

R. Abuter ◽

A. Amorim ◽

M. Bauböck ◽

J. P. Berger ◽

...

Keyword(s):

Black Hole ◽

Reference Frame ◽

Adaptive Optics ◽

Galactic Centre ◽

Massive Black Hole ◽

Central Mass ◽

Black Hole Candidate ◽

Beam Combiner ◽

Direct Measurements ◽

Sgr A

The star S2 orbiting the compact radio source Sgr A* is a precision probe of the gravitational field around the closest massive black hole (candidate). Over the last 2.7 decades we have monitored the star’s radial velocity and motion on the sky, mainly with the SINFONI and NACO adaptive optics (AO) instruments on the ESO VLT, and since 2017, with the four-telescope interferometric beam combiner instrument GRAVITY. In this Letter we report the first detection of the General Relativity (GR) Schwarzschild Precession (SP) in S2’s orbit. Owing to its highly elliptical orbit (e = 0.88), S2’s SP is mainly a kink between the pre-and post-pericentre directions of motion ≈±1 year around pericentre passage, relative to the corresponding Kepler orbit. The superb 2017−2019 astrometry of GRAVITY defines the pericentre passage and outgoing direction. The incoming direction is anchored by 118 NACO-AO measurements of S2’s position in the infrared reference frame, with an additional 75 direct measurements of the S2-Sgr A* separation during bright states (“flares”) of Sgr A*. Our 14-parameter model fits for the distance, central mass, the position and motion of the reference frame of the AO astrometry relative to the mass, the six parameters of the orbit, as well as a dimensionless parameter fSP for the SP (fSP = 0 for Newton and 1 for GR). From data up to the end of 2019 we robustly detect the SP of S2, δϕ ≈ 12′ per orbital period. From posterior fitting and MCMC Bayesian analysis with different weighting schemes and bootstrapping we find fSP = 1.10 ± 0.19. The S2 data are fully consistent with GR. Any extended mass inside S2’s orbit cannot exceed ≈0.1% of the central mass. Any compact third mass inside the central arcsecond must be less than about 1000 M⊙.

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External energy paradigm for black holes

International Journal of Modern Physics A ◽

10.1142/s0217751x18440256 ◽

2018 ◽

Vol 33 (31) ◽

pp. 1844025 ◽

Cited By ~ 1

Author(s):

Yuan K. Ha

Keyword(s):

Black Holes ◽

Black Hole ◽

Gravitational Energy ◽

Electrostatic Energy ◽

New Paradigm ◽

External Energy ◽

Quantum Particles ◽

Remarkable Result ◽

The Moment ◽

Constituent Mass

A new paradigm for black holes is introduced. It is known as the External Energy Paradigm. The paradigm asserts that all energies of a black hole are external quantities; they are absent inside the horizon. These energies include constituent mass, gravitational energy, electrostatic energy, rotational energy, heat energy, etc. As a result, quantum particles with charges and spins cannot exist inside the black hole. To validate the conclusion, we derive the moment of inertia of a Schwarzschild black hole and find that it is exactly equal to mass [Formula: see text] (Schwarzschild radius)2, indicating that all mass of the black hole is located at the horizon. This remarkable result can resolve several long-standing paradoxes in black hole theory; such as why entropy is proportional to area and not to volume, the singularity problem, the information loss problem and the perplexing firewall controversy.

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Cosmological simulations of massive black hole seeds: predictions for next-generation electromagnetic and gravitational wave observations

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz3309 ◽

2019 ◽

Vol 491 (4) ◽

pp. 4973-4992

Author(s):

C DeGraf ◽

D Sijacki

Keyword(s):

Black Holes ◽

Black Hole ◽

Cosmic Time ◽

Host Galaxy ◽

Electromagnetic Spectrum ◽

Massive Black Hole ◽

Cosmological Simulations ◽

Seed Formation ◽

Order Of Magnitude ◽

Low Mass

ABSTRACT We study how statistical properties of supermassive black holes depend on the frequency and conditions for massive seed formation in cosmological simulations of structure formation. We develop a novel method to recalculate detailed growth histories and merger trees of black holes within the framework of the Illustris simulation for several seed formation models, including a physically motivated model where black hole seeds only form in progenitor galaxies that conform to the conditions for direct collapse black hole formation. While all seed models considered here are in a broad agreement with present observational constraints on black hole populations from optical, UV, and X-ray studies, we find that they lead to widely different black hole number densities and halo occupation fractions, which are currently observationally unconstrained. In terms of future electromagnetic spectrum observations, the faint-end quasar luminosity function and the low-mass-end black hole–host galaxy scaling relations are very sensitive to the specific massive seed prescription. Specifically, the direct collapse model exhibits a seeding efficiency that decreases rapidly with cosmic time and produces much fewer black holes in low-mass galaxies, in contrast to the original Illustris simulation. We further find that the total black hole merger rate varies by more than one order of magnitude for different seed models, with the redshift evolution of the chirp mass changing as well. Supermassive black hole merger detections with LISA and International Pulsar Timing Array may hence provide the most direct means of constraining massive black hole seed formation in the early Universe.

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Magnetized Particle Motion around Black Holes in Conformal Gravity: Can Magnetic Interaction Mimic Spin of Black Holes?

Universe ◽

10.3390/universe6030044 ◽

2020 ◽

Vol 6 (3) ◽

pp. 44 ◽

Cited By ~ 10

Author(s):

Kamoliddin Haydarov ◽

Ahmadjon Abdujabbarov ◽

Javlon Rayimbaev ◽

Bobomurat Ahmedov

Keyword(s):

Magnetic Field ◽

Black Holes ◽

Black Hole ◽

Particle Motion ◽

Center Of Mass ◽

Conformal Gravity ◽

Mass Energy ◽

Particle Collisions ◽

Center Of Mass Energy ◽

Sgr A

Magnetized particle motion around black holes in conformal gravity immersed in asymptotically uniform magnetic field has been studied. We have also analyzed the behavior of magnetic fields near the horizon of the black hole in conformal gravity and shown that with the increase of conformal parameters L and N the value of angular component of magnetic field at the stellar surface decreases. The maximum value of the effective potential corresponding to circular motion of the magnetized particle increases with the increase of conformal parameters. It is shown that in all cases of neutral, charged and magnetized particle collisions in the black hole environment the center-of-mass energy decreases with the increase of conformal parameters L and N. In the case of the magnetized and negatively charged particle collisions, the innermost collision point with the maximum center-of-mass energy comes closer to the central object due to the effects of the parameters of the conformal gravity. We have applied the results to the real astrophysical scenario when a pulsar treated as a magnetized particle is orbiting the super massive black hole (SMBH) Sgr A* in the center of our galaxy in order to obtain the estimation of magnetized compact object’s orbital parameter. The possible detection of pulsar in Sgr A* close environment can provide constraints on black hole parameters. Here we have shown that there is degeneracy between spin of SMBH and ambient magnetic field and consequently the interaction of magnetic field ∼ 10 2 Gauss with magnetic moment of magnetized neutron star can in principle mimic spin of Kerr black holes up to 0.6 .

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Clarification of the formation process of the super massive black hole by Infrared astrometric satellite, Small-JASMINE

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317005476 ◽

2017 ◽

Vol 12 (S330) ◽

pp. 360-361 ◽

Cited By ~ 1

Author(s):

Taihei Yano ◽

Keyword(s):

Black Holes ◽

Black Hole ◽

Phase Space ◽

Formation Process ◽

Near Infrared ◽

Galactic Center ◽

Space Distribution ◽

Massive Black Hole ◽

Phase Space Distribution ◽

Merging Process

AbstractSmall-JASMINE (hearafter SJ), infrared astrometric satellite, will measure the positions and the proper motions which are located around the Galactic center, by operating at near infrared wave-lengths. SJ will clarify the formation process of the super massive black hole (hearafter SMBH) at the Galactic center. In particular, SJ will determine whether the SMBH was formed by a sequential merging of multiple black holes. The clarification of this formation process of the SMBH will contribute to a better understanding of merging process of satellite galaxies into the Galaxy, which is suggested by the standard galaxy formation scenario. A numerical simulation (Tanikawa and Umemura, 2014) suggests that if the SMBH was formed by the merging process, then the dynamical friction caused by the black holes have influenced the phase space distribution of stars. The phase space distribution measured by SJ will make it possible to determine the occurrences of the merging process.

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CLUES FOR THE COMPOSITION OF RELATIVISTIC MICROQUASAR JETS

International Journal of Modern Physics D ◽

10.1142/s0218271808013613 ◽

2008 ◽

Vol 17 (10) ◽

pp. 1947-1952 ◽

Cited By ~ 5

Author(s):

SEBASTIAN HEINZ

Keyword(s):

Kinetic Energy ◽

Energy Flux ◽

Significant Contribution ◽

Total Kinetic Energy ◽

Singular Case ◽

Relativistic Jets ◽

Ss 433 ◽

Jet Power ◽

Entire Ensemble

We discuss the evidence for proton loading in relativistic jets from microquasars in light of recent constraints on the jet power. We argue that, both in the case of the Cygnus X-1 jet and the entire ensemble of Galactic microquasars, the evidence points towards a significant contribution to the total kinetic energy flux from cold protons. However, as with all other methods of constraining jet composition (except for the singular case of SS 433), a number of alternative, though maybe less plausible, explanations exist. In light of this continued elusiveness of a single slam-dunk argument for proton loading, the best we can hope for is a continuing accumulation of bits of evidence such as these which will, on the whole, form a preponderance of evidence against pure pair jets.

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The Role of Gravitational Instabilities in the Feeding of Supermassive Black Holes

Advances in Astronomy ◽

10.1155/2012/846875 ◽

2012 ◽

Vol 2012 ◽

pp. 1-15 ◽

Cited By ~ 4

Author(s):

Giuseppe Lodato

Keyword(s):

Black Holes ◽

Black Hole ◽

High Redshift ◽

Supermassive Black Holes ◽

Point Of View ◽

Accretion Discs ◽

Theoretical Point ◽

Interstellar Gas ◽

Massive Black Hole

I review the recent progresses that have been obtained, especially through the use of high-resolution numerical simulations, on the dynamics of self-gravitating accretion discs. A coherent picture is emerging, where the disc dynamics is controlled by a small number of parameters that determine whether the disc is stable or unstable, whether the instability saturates in a self-regulated state or runs away into fragmentation, and whether the dynamics is local or global. I then apply these concepts to the case of AGN discs, discussing the implications of such evolution on the feeding of supermassive black holes. Nonfragmenting, self-gravitating discs appear to play a fundamental role in the process of formation of massive black hole seeds at high redshift ( 10–15) through direct gas collapse. On the other hand, the different cooling properties of the interstellar gas at low redshifts determine a radically different behaviour for the outskirts of the accretion discs feeding typical AGNs. Here the situation is much less clear from a theoretical point of view, and while several observational clues point to the important role of massive discs at a distance of roughly a parsec from their central black hole, their dynamics is still under debate.

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