scholarly journals Growth of Accreting Supermassive Black Hole Seeds and Neutrino Radiation

2015 ◽  
Vol 2015 ◽  
pp. 1-30 ◽  
Author(s):  
Gagik Ter-Kazarian

In the framework of microscopic theory of black hole (MTBH), which explores the most important processes of rearrangement of vacuum state and spontaneous breaking of gravitation gauge symmetry at huge energies, we have undertaken a large series of numerical simulations with the goal to trace an evolution of the mass assembly history of 377 plausible accreting supermassive black hole seeds in active galactic nuclei (AGNs) to the present time and examine the observable signatures today. Given the redshifts, masses, and luminosities of these black holes at present time collected from the literature, we compute the initial redshifts and masses of the corresponding seed black holes. For the present masses MBH/M⊙≃1.1×106 to 1.3×1010 of 377 black holes, the computed intermediate seed masses are ranging from MBHSeed/M⊙≃26.4 to 2.9×105. We also compute the fluxes of ultrahigh energy (UHE) neutrinos produced via simple or modified URCA processes in superdense protomatter nuclei. The AGNs are favored as promising pure UHE neutrino sources, because the computed neutrino fluxes are highly beamed along the plane of accretion disk, peaked at high energies, and collimated in smaller opening angle (θ≪1).

Author(s):  
G. Ter-Kazarian

We briefly review the observable signature and computational efforts of growth and merging phenomena of astrophysical black holes. We examine the meaning, and assess the validity of such properties within theoretical framework of the long-standing phenomenological model of black holes (PMBHs), being a peculiar repercussion of general relativity. We provide a discussion of some key objectives with the analysis aimed at clarifying the current situation of the subject. It is argued that such exotic hypothetical behaviors seem nowhere near true if one applies the PMBH. Refining our conviction that a complete, self-consistent gravitation theory will smear out singularities at huge energies, and give the solution known deep within the BH, we employ the microscopic theory of black hole (MTBH), which has explored the most important novel aspects expected from considerable change of properties of space-time continuum at spontaneous breaking of gravitation gauge symmetry far above nuclear density. It may shed further light upon the growth and merging phenomena of astrophysical BHs.


2021 ◽  
Vol 503 (3) ◽  
pp. 3629-3642
Author(s):  
Colin DeGraf ◽  
Debora Sijacki ◽  
Tiziana Di Matteo ◽  
Kelly Holley-Bockelmann ◽  
Greg Snyder ◽  
...  

ABSTRACT With projects such as Laser Interferometer Space Antenna (LISA) and Pulsar Timing Arrays (PTAs) expected to detect gravitational waves from supermassive black hole mergers in the near future, it is key that we understand what we expect those detections to be, and maximize what we can learn from them. To address this, we study the mergers of supermassive black holes in the Illustris simulation, the overall rate of mergers, and the correlation between merging black holes and their host galaxies. We find these mergers occur in typical galaxies along the MBH−M* relation, and that between LISA and PTAs we expect to probe the full range of galaxy masses. As galaxy mergers can trigger star formation, we find that galaxies hosting low-mass black hole mergers tend to show a slight increase in star formation rates compared to a mass-matched sample. However, high-mass merger hosts have typical star formation rates, due to a combination of low gas fractions and powerful active galactic nucleus feedback. Although minor black hole mergers do not correlate with disturbed morphologies, major mergers (especially at high-masses) tend to show morphological evidence of recent galaxy mergers which survive for ∼500 Myr. This is on the same scale as the infall/hardening time of merging black holes, suggesting that electromagnetic follow-ups to gravitational wave signals may not be able to observe this correlation. We further find that incorporating a realistic time-scale delay for the black hole mergers could shift the merger distribution towards higher masses, decreasing the rate of LISA detections while increasing the rate of PTA detections.


2019 ◽  
Vol 14 (S351) ◽  
pp. 80-83 ◽  
Author(s):  
Melvyn B. Davies ◽  
Abbas Askar ◽  
Ross P. Church

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.


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.


Science ◽  
2019 ◽  
Vol 366 (6461) ◽  
pp. 97-100 ◽  
Author(s):  
H. Umehata ◽  
M. Fumagalli ◽  
I. Smail ◽  
Y. Matsuda ◽  
A. M. Swinbank ◽  
...  

Cosmological simulations predict that the Universe contains a network of intergalactic gas filaments, within which galaxies form and evolve. However, the faintness of any emission from these filaments has limited tests of this prediction. We report the detection of rest-frame ultraviolet Lyman-α radiation from multiple filaments extending more than one megaparsec between galaxies within the SSA22 protocluster at a redshift of 3.1. Intense star formation and supermassive black-hole activity is occurring within the galaxies embedded in these structures, which are the likely sources of the elevated ionizing radiation powering the observed Lyman-α emission. Our observations map the gas in filamentary structures of the type thought to fuel the growth of galaxies and black holes in massive protoclusters.


2007 ◽  
Vol 3 (S245) ◽  
pp. 219-222
Author(s):  
Philip F. Hopkins

AbstractWe study observed correlations between supermassive black hole (BHs) and the properties of their host galaxies, and show that the observations define a BH “fundamental plane” (BHFP), of the form $\mbh\propto\sigma^{3.0\pm0.3}\,\re^{0.43\pm0.19}$ or $\mbh\propto\mstar^{0.54\pm0.17}\,\sigma^{2.2\pm0.5}$, analogous to the FP of elliptical galaxies. The BHFP is preferred over a simple relation between MBH and any of σ, M*, Mdyn, or Re alone at > 3 σ (99.9%) significance. The existence of this BHFP has important implications for the formation of supermassive BHs and the masses of the very largest black holes, and immediately resolves several apparent conflicts between the BH masses expected and measured for outliers in both the MBH − σ and MBH − M* relations.


2015 ◽  
Vol 24 (13) ◽  
pp. 1545005 ◽  
Author(s):  
K. M. Belotsky ◽  
A. A. Kirillov ◽  
S. G. Rubin

Here, we briefly discuss the possibility to solve simultaneously with primordial black holes (PBHs) the problems of dark matter (DM), reionization of the universe, origin of positron line from Galactic center and supermassive black hole (BH) in it. Discussed scenario can naturally lead to a multiple-peak broad-mass-range distribution of PBHs in mass, which is necessary for simultaneous solution of the problems.


Author(s):  
G. Ter-Kazarian

We review the Ambartsumian’s cosmogony, which involves his fundamental ideas on Stellar Associations and eruptive Activity of Galactic Nuclei, where the creation process is at work. Itis caused by the violent outburst events of transformations of superdense matter in supermassive compact bodies in galaxies, away from the accretion physics. We discuss the pioneering works of V.A. Armbartsumyan and G.S. Saakyan carried out at Byurakan Observatory in the earlier of 1960’s towards the physics of equilibrium configurations of degenerate superdense gas of elementary particles, particularity, the hyperon configurations of stellar masses. These issues have been comprehensively developed later on by G. Ter-Kazarian in the proposed theory of distortion of space-time continuum(DSTC) at huge energies (respectively, at short distances < 0.4fm), which underlies the microscopic theory of black hole (MTBH). The MTBH has further proved to be quite fruitful for ultra-high energy astrophysics. The MTBH explores the most important process of spontaneous breaking of gravitation gauge symmetry at huge energies, and thereof for that of re-arrangement of vacuum state. As a corollary, MTBH has smeared out the central singularities of BHs, and makes room for their growth and merging behavior, with implications of vital interest for high energy astrophysics.


Universe ◽  
2019 ◽  
Vol 5 (12) ◽  
pp. 220 ◽  
Author(s):  
Pedro Cunha ◽  
Carlos Herdeiro ◽  
Eugen Radu

Hypothetical ultralight bosonic fields will spontaneously form macroscopic bosonic halos around Kerr black holes, via superradiance, transferring part of the mass and angular momentum of the black hole into the halo. Such a process, however, is only efficient if resonant—when the Compton wavelength of the field approximately matches the gravitational scale of the black hole. For a complex-valued field, the process can form a stationary, bosonic field black hole equilibrium state—a black hole with synchronised hair. For sufficiently massive black holes, such as the one at the centre of the M87 supergiant elliptic galaxy, the hairy black hole can be robust against its own superradiant instabilities, within a Hubble time. Studying the shadows of such scalar hairy black holes, we constrain the amount of hair which is compatible with the Event Horizon Telescope (EHT) observations of the M87 supermassive black hole, assuming the hair is a condensate of ultralight scalar particles of mass μ ∼ 10 − 20 eV, as to be dynamically viable. We show the EHT observations set a weak constraint, in the sense that typical hairy black holes that could develop their hair dynamically, are compatible with the observations, when taking into account the EHT error bars and the black hole mass/distance uncertainty.


2014 ◽  
Vol 10 (S312) ◽  
pp. 43-47
Author(s):  
Shuo Li ◽  
Fukun Liu ◽  
Peter Berczik ◽  
Rainer Spurzem

AbstractSupermassive black hole binaries (SMBHBs) are the products of frequent galaxy mergers. It is very hard to be detected in quiescent galaxy. By using one million particle direct N-body simulations on special many-core hardware (GPU cluster), we study the dynamical co-evolution of SMBHB and its surrounding stars, specially focusing on the evolution of stellar tidal disruption event (TDE) rates before and after the coalescence of the SMBHB. We find a boosted TDE rate during the merger of the galaxies. After the coalescence of two supermassive black holes (SMBHs), the post-merger SMBH can get a kick velocity due to the anisotropic GW radiations. Our results about the recoiling SMBH, which oscillates around galactic center, show that most of TDEs are contributed by unbound stars when the SMBH passing through galactic center. In addition, the TDE light curve in SMBHB system is significantly different from the curve for single SMBH, which can be used to identify the SMBHB.


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