Gamma Ray Jets and Black Hole Magnetospheres in Active Galactic Nuclei

1994 ◽  
pp. 171-180 ◽  
Author(s):  
R. D. Blandford
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Galactic Nuclei

scholarly journals HIGH-ENERGY EMISSION FROM JET–CLOUD INTERACTIONS IN AGNs

2010 ◽  
Vol 19 (06) ◽  
pp. 931-936 ◽  
Author(s):  
ANABELLA T. ARAUDO ◽  
VALENTÍ BOSCH-RAMON ◽  
GUSTAVO E. ROMERO
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Line Emission ◽  
Galactic Nuclei ◽  
Small Region ◽  
High Energy ◽  
Energy Emission ◽  
Central Regions ◽  
High Energy Emission

Active galactic nuclei present continuum and line emission. The emission lines are originated by gas located close to the central supermassive black hole. Some of these lines are broad, and would be produced in a small region called broad-line region. This region could be formed by clouds surrounding the central black hole. In this work, we study the interaction of such clouds with the base of the jets in active galactic nuclei, and we compute the produced high-energy emission. We focus on sources with low luminosities in the inner jet regions, to avoid strong gamma-ray absorption. We find that the resulting high-energy radiation may be significant in Centaurus A. Also, this phenomenon might be behind the variable gamma-ray emission detected in M87, if very large dark clouds are present. The detection of jet–cloud interactions in active galactic nuclei would give information on the properties of the jet base and the very central regions.

scholarly journals Radio Galaxies at VHE Energies

Galaxies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 116 ◽  
Author(s):  
Frank Rieger ◽  
Amir Levinson
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
Radio Galaxies ◽  
Concise Overview ◽  
Recent Developments ◽  
Γ Ray ◽  
Very High

Radio Galaxies have by now emerged as a new γ-ray emitting source class on the extragalactic sky. Given their remarkable observed characteristics, such as unusual gamma-ray spectra or ultrafast VHE variability, they represent unique examples to probe the nature and physics of active galactic nuclei (AGN) in general. This review provides a compact summary of their observed characteristics at very high γ-ray energies (VHE; greater than 100 GeV) along with a discussion of their possible physics implications. A particular focus is given to a concise overview of fundamental concepts concerning the origin of variable VHE emission, including recent developments in black hole gap physics.

scholarly journals Gamma-Ray Astrophysics in the Time Domain

Galaxies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 28 ◽  
Author(s):  
Frank Rieger
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Time Domain ◽  
Gamma Ray ◽  
Black Hole Physics ◽  
Galactic Nuclei ◽  
Statistical Tools ◽  
Gamma Ray Astronomy ◽  
The Time Domain

The last few years have seen gamma-ray astronomy maturing and advancing in the field of time-domain astronomy, utilizing source variability on timescales over many orders of magnitudes, from a decade down to a few minutes and shorter, depending on the source. This review focuses on some of the key science issues and conceptual developments concerning the timing characteristics of active galactic nuclei (AGN) at gamma-ray energies. It highlights the relevance of adequate statistical tools and illustrates that the developments in the gamma-ray domain bear the potential to fundamentally deepen our understanding of the nature of the emitting source and the link between accretion dynamics, black hole physics, and jet ejection.

BLACK HOLES IN GAMMA RAY BURSTS AND GALACTIC NUCLEI

2013 ◽  
Vol 22 (11) ◽  
pp. 1360008 ◽  
Author(s):  
REMO RUFFINI ◽  
C. R. ARGÜELLES ◽  
B. M. O. FRAGA ◽  
A. GERALICO ◽  
H. QUEVEDO ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
Future Research ◽  
Galactic Halos ◽  
Unified Approach ◽  
Massive Black Holes ◽  
The Moment

Current research marks a clear success in identifying the moment of formation of a Black Hole of ~ 10M⊙, with the emission of a Gamma Ray Burst. This explains in terms of the 'Blackholic Energy' the source of the energy of these astrophysical systems. Their energetics up to 1054 erg, make them detectable all over our Universe. Concurrently a new problematic has been arising related to: (a) The evidence of Dark Matter in galactic halos; (b) The origin of the Super Massive Black Holes in active galactic nuclei and Quasars and (c) The purported existence of a Black Hole in the Center of our Galaxy. These three aspects of this new problematic have been traditionally approached independently. We propose an unified approach to all three of them based on a system of massive self-gravitating neutrinos in General Relativity. Perspectives of future research are presented.

scholarly journals The quantum emission of an alive black hole

2021 ◽  
pp. 2141003
Author(s):  
J. A. Rueda ◽  
R. Ruffini
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Kerr Black Hole ◽  
Galactic Nuclei ◽  
New Physics ◽  
Rotational Energy ◽  
Gamma Ray Bursts ◽  
Astrophysical Objects

A long march of 50 years of successive theoretical progress and new physics discovered using observations of gamma-ray bursts has finally led to the formulation of an efficient mechanism able to extract the rotational energy of a Kerr black hole to power these most energetic astrophysical sources and active galactic nuclei. We here present the salient features of this long-sought mechanism, based on gravito-electrodynamics, and which represents an authentic shift of paradigm of black holes as forever “alive” astrophysical objects.

scholarly journals Epicyclic Oscillations around Simpson–Visser Regular Black Holes and Wormholes

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 279
Author(s):  
Zdeněk Stuchlík ◽  
Jaroslav Vrba
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Observational Data ◽  
High Frequency ◽  
Galactic Nuclei ◽  
Supermassive Black Holes ◽  
Periodic Oscillations ◽  
High Length ◽  
Circular Geodesic

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.

scholarly journals Gamma-Ray and Neutrino Signals from Accretion Disk Coronae of Active Galactic Nuclei

Galaxies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 36
Author(s):  
Yoshiyuki Inoue ◽  
Dmitry Khangulyan ◽  
Akihiro Doi
Keyword(s):  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
High Energy ◽  
Thermal Activity ◽  
X Ray ◽  
Cascade Models ◽  
Coronal Activity ◽  
Ngc 1068 ◽  
High Energy Particles

To explain the X-ray spectra of active galactic nuclei (AGN), non-thermal activity in AGN coronae such as pair cascade models has been extensively discussed in the past literature. Although X-ray and gamma-ray observations in the 1990s disfavored such pair cascade models, recent millimeter-wave observations of nearby Seyferts have established the existence of weak non-thermal coronal activity. In addition, the IceCube collaboration reported NGC 1068, a nearby Seyfert, as the hottest spot in their 10 yr survey. These pieces of evidence are enough to investigate the non-thermal perspective of AGN coronae in depth again. This article summarizes our current observational understanding of AGN coronae and describes how AGN coronae generate high-energy particles. We also provide ways to test the AGN corona model with radio, X-ray, MeV gamma ray, and high-energy neutrino observations.

scholarly journals The Alignment of Disk and Black Hole Spins in Active Galactic Nuclei

1998 ◽  
Vol 506 (2) ◽  
pp. L97-L100 ◽  
Author(s):  
Priyamvada Natarajan ◽  
J. E. Pringle
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei
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