On High-energy Particles in Accretion Disk Coronae of Supermassive Black Holes: Implications for MeV Gamma-rays and High-energy Neutrinos from AGN Cores

2019 ◽  
Vol 880 (1) ◽  
pp. 40 ◽  
Author(s):  
Yoshiyuki Inoue ◽  
Dmitry Khangulyan ◽  
Susumu Inoue ◽  
Akihiro Doi
Keyword(s):  
Black Holes ◽  
Accretion Disk ◽  
Gamma Rays ◽  
High Energy ◽  
Supermassive Black Holes ◽  
High Energy Neutrinos ◽  
High Energy Particles

scholarly journals Influence of Cosmic Repulsion and Magnetic Fields on Accretion Disks Rotating around Kerr Black Holes

Universe ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 26 ◽  
Author(s):  
Zdeněk Stuchlík ◽  
Martin Kološ ◽  
Jiří Kovář ◽  
Petr Slaný ◽  
Arman Tursunov
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Magnetic Fields ◽  
Accretion Disks ◽  
Vacuum Energy ◽  
High Energy ◽  
Supermassive Black Holes ◽  
Ultra High Energy ◽  
Thin And Thick Disks ◽  
High Energy Particles

We present a review of the influence of cosmic repulsion and external magnetic fields on accretion disks rotating around rotating black holes and on jets associated with these rotating configurations. We consider both geometrically thin and thick disks. We show that the vacuum energy represented by the relic cosmological constant strongly limits extension of the accretion disks that is for supermassive black holes comparable to extension of largest galaxies, and supports collimation of jets at large distances from the black hole. We further demonstrate that an external magnetic field crucially influences the fate of ionized Keplerian disks causing creation of winds and jets, enabling simultaneously acceleration of ultra-high energy particles with energy up to 10 21 eV around supermassive black holes with M ∼ 10 10 M ⊙ surrounded by sufficiently strong magnetic field with B ∼ 10 4 G. We also show that the external magnetic fields enable existence of “levitating” off-equatorial clouds or tori, along with the standard equatorial toroidal structures, if these carry a non-vanishing, appropriately distributed electric charge.

scholarly journals Correlation of high energy neutrinos and gamma rays on the direction of Fermi Bubbles

2019 ◽  
Author(s):  
Paola Alvarez Hurtado ◽  
Nissim Fraija ◽  
Antonio Galván ◽  
Antonio Marinelli
Keyword(s):  
Gamma Rays ◽  
High Energy ◽  
High Energy Neutrinos

scholarly journals Very High-Energy Emission from the Direct Vicinity of Rapidly Rotating Black Holes

Galaxies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 122 ◽  
Author(s):  
Kouichi Hirotani
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Black Hole ◽  
Electric Field ◽  
Gamma Rays ◽  
Accretion Rate ◽  
High Energy ◽  
Relativistic Electrons ◽  
Field Lines ◽  
The Magnetic Field

When a black hole accretes plasmas at very low accretion rate, an advection-dominated accretion flow (ADAF) is formed. In an ADAF, relativistic electrons emit soft gamma-rays via Bremsstrahlung. Some MeV photons collide with each other to materialize as electron-positron pairs in the magnetosphere. Such pairs efficiently screen the electric field along the magnetic field lines, when the accretion rate is typically greater than 0.03–0.3% of the Eddington rate. However, when the accretion rate becomes smaller than this value, the number density of the created pairs becomes less than the rotationally induced Goldreich–Julian density. In such a charge-starved magnetosphere, an electric field arises along the magnetic field lines to accelerate charged leptons into ultra-relativistic energies, leading to an efficient TeV emission via an inverse-Compton (IC) process, spending a portion of the extracted hole’s rotational energy. In this review, we summarize the stationary lepton accelerator models in black hole magnetospheres. We apply the model to super-massive black holes and demonstrate that nearby low-luminosity active galactic nuclei are capable of emitting detectable gamma-rays between 0.1 and 30 TeV with the Cherenkov Telescope Array.

scholarly journals Magnetized Black Holes: Ionized Keplerian Disks and Acceleration of Ultra-High Energy Particles

Proceedings ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 13 ◽  
Author(s):  
Zdeněk Stuchlík ◽  
Martin Kološ ◽  
Arman Tursunov
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Magnetic Fields ◽  
High Energy ◽  
Weak Magnetic Fields ◽  
Motion Transformation ◽  
Penrose Process ◽  
Field Lines ◽  
High Energy Particles ◽  
Quasiperiodic Oscillations

Properties of charged particle motion in the field of magnetized black holes (BHs) imply four possible regimes of behavior of ionized Keplerian disks: survival in regular epicyclic motion, transformation into chaotic toroidal state, destruction due to fall into the BHs, destruction due to escape along magnetic field lines (escape to infinity for disks orbiting Kerr BHs). The regime of the epicyclic motion influenced by very weak magnetic fields can be related to the observed high-frequency quasiperiodic oscillations. In the case of very strong magnetic fields particles escaping to infinity could form UHECR due to extremely efficient magnetic Penrose process – protons with energy E > 10 21 eV can be accelerated by supermassive black holes with M ∼ 10 10 M ⊙ immersed in magnetic field with B ∼ 10 4 Gs.

Determination of supermassive black hole spins in active galactic nuclei

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.

scholarly journals Particle Acceleration in High-Energy Gamma-Ray Sources

1994 ◽  
Vol 142 ◽  
pp. 877-881
Author(s):  
David Eichler
Keyword(s):  
Gamma Rays ◽  
Production Efficiency ◽  
Gamma Ray ◽  
High Energy ◽  
Thick Target ◽  
Shock Acceleration ◽  
High Production Efficiency ◽  
Energy Gamma ◽  
High Production ◽  
High Energy Particles

AbstractMany proficient gamma-ray sources show energy spectra that are consistent with E−2 primary spectra. Such sources include recently identified gamma-ray quasars and some gamma-ray bursts. Assuming thick target conversion, this is consistent with shock acceleration, and the dominance of the gamma rays of the luminosity is also consistent with previous predictions of high production efficiency of fresh cosmic rays in shocks. The spectral cutoffs in the gamma rays may offer clues as to whether the high-energy particles are electrons or protons. Resolution of this matter might have implications for the nature of the sources and for theory of shock accelerated electrons.Subject headings: acceleration of particles — gamma rays: bursts — shock waves

scholarly journals Neutrinos from Relativistic Outflows of Fast Spinning Magnetars

2005 ◽  
Vol 22 (2) ◽  
pp. 157-161 ◽  
Author(s):  
Qinghuan Luo
Keyword(s):  
Gamma Rays ◽  
Neutrino Flux ◽  
Rotation Period ◽  
High Energy ◽  
Boundary Region ◽  
Stellar Envelope ◽  
Energetic Ions ◽  
Short Rotation ◽  
Polar Gap ◽  
High Energy Neutrinos

AbstractPulsars may be born with a short rotation period of milliseconds with the magnetic field amplified through dynamo processes up to ∼1015–1016 G. Such millisecond magnetars spin down rapidly, emitting bursts of high-energy neutrinos and gamma rays. Specifically, acceleration of ions in both the polar gap (as in a normal pulsar) and the relativistic magnetar wind is considered. In both cases ions can be accelerated to ultra-high energies and these energetic ions can lead to production of high-energy neutrinos and gamma rays through interaction with thermal radiation from the hot neutron star or the heated inner boundary region of the stellar envelope as the result of the deposition of energy by the magnetar wind. The detectability of the neutrino flux by a kilometre-scale neutrino detector such as the planned IceCube neutrino observatory is discussed.

Sign in / Sign up

Export Citation Format

Share Document