scholarly journals Diffuse gamma ray background from annihilating dark matter in density spikes around supermassive black holes

2014 ◽  
Vol 89 (4) ◽  
Author(s):  
Alexander Belikov ◽  
Joseph Silk
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Gamma Ray ◽  
Supermassive Black Holes

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

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.

scholarly journals The M-sigma relation of supermassive black holes from the scalar field dark matter

2020 ◽  
Vol 35 (19) ◽  
pp. 2050155
Author(s):  
Jae-Weon Lee ◽  
Hyeong-Chan Kim ◽  
Jungjai Lee
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Scalar Field ◽  
Numerical Study ◽  
Dark Matter Particle ◽  
Einstein Condensate ◽  
Supermassive Black Holes ◽  
Dark Matter Halo ◽  
Wave Nature ◽  
Velocity Dispersions

We show a relation between the mass of supermassive black holes in galaxies and the velocity dispersions of their bulges in the scalar field or the Bose–Einstein condensate dark matter model. The gravity of the central black holes changes boundary conditions of the scalar field at the galactic centers. Owing to the wave nature of the dark matter, this significantly changes the galactic dark matter halo profiles even though the black holes are much lighter than the bulges. As a result the heavier the black holes are, the more compact the bulges are, and hence the larger the velocity dispersions are. This tendency is verified by a numerical study showing the M-sigma relation reproduced with the dark matter particle mass [Formula: see text] eV.

scholarly journals CAN DIRECT COLLAPSE BLACK HOLES LAUNCH GAMMA-RAY BURSTS AND GROW TO SUPERMASSIVE BLACK HOLES?

2015 ◽  
Vol 810 (1) ◽  
pp. 64 ◽  
Author(s):  
Tatsuya Matsumoto ◽  
Daisuke Nakauchi ◽  
Kunihito Ioka ◽  
Alexander Heger ◽  
Takashi Nakamura
Keyword(s):  
Black Holes ◽  
Gamma Ray ◽  
Supermassive Black Holes ◽  
Gamma Ray Bursts

A SHORT, CRITICAL REVIEW ON GAMMA-RAY EMISSION FROM GALAXY CLUSTERS

2009 ◽  
Vol 18 (10) ◽  
pp. 1541-1544
Author(s):  
SERGIO COLAFRANCESCO
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Cosmic Rays ◽  
Galaxy Clusters ◽  
Critical Review ◽  
Particle Physics ◽  
Gamma Ray ◽  
Gamma Ray Emission ◽  
The Impact

We discuss the relevance of gamma-ray observations of galaxy clusters, to unveil several issues that are relevant for Cosmology and Astro-Particle Physics of cosmic structures: the nature of Dark Matter, the origin of cosmic rays and the impact of black holes.

scholarly journals Dark matter accretion into supermassive black holes

2008 ◽  
Vol 77 (6) ◽  
Author(s):  
Sébastien Peirani ◽  
J. A. de Freitas Pacheco
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Supermassive Black Holes
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