scholarly journals Particle acceleration and the origin of the very high energy emission around black holes and relativistic jets

2020 ◽  
Vol 14 (S342) ◽  
pp. 13-18
Author(s):  
Elisabete M. de Gouveia Dal Pino ◽  
Grzegorz Kowal ◽  
Luis Kadowaki ◽  
Tania E. Medina-Torrejón ◽  
Yosuke Mizuno ◽  
...  
Keyword(s):  
Black Hole ◽  
Particle Acceleration ◽  
Magnetic Reconnection ◽  
High Energy ◽  
Black Hole Binaries ◽  
Mhd Instabilities ◽  
Test Particles ◽  
Very High Energy ◽  
General Relativistic ◽  
Very High

AbstractParticle acceleration induced by fast magnetic reconnection may help to solve current puzzles related to the interpretation of the very high energy (VHE) and neutrino emissions from AGNs and compact sources in general. Our general relativistic-MHD simulations of accretion disk-corona systems reveal the growth of turbulence driven by MHD instabilities that lead to the development of fast magnetic reconnection in the corona. In addition, our simulations of relativistic MHD jets reveal the formation of several sites of fast reconnection induced by current-driven kink turbulence. The injection of thousands of test particles in these regions causes acceleration up to energies of several PeVs, thus demonstrating the ability of this process to accelerate particles and produce VHE and neutrino emission, specially in blazars. Finally, we discuss how reconnection can also explain the observed VHE luminosity-black hole mass correlation, involving hundreds of non-blazar sources like Perseus A, and black hole binaries.

scholarly journals PARTICLE ACCELERATION CLOSE TO THE SUPERMASSIVE BLACK HOLE HORIZON: THE CASE OF M87

2008 ◽  
Vol 17 (09) ◽  
pp. 1569-1575 ◽  
Author(s):  
F. M. RIEGER ◽  
F. A. AHARONIAN
Keyword(s):  
Black Hole ◽  
Particle Acceleration ◽  
Diagnostic Tool ◽  
Radio Galaxy ◽  
High Energy ◽  
Supermassive Black Hole ◽  
Important Diagnostic Tool ◽  
Very High Energy ◽  
Emission Models ◽  
Very High

The radio galaxy M87 has recently been found to be a rapidly variable TeV emitting source. We analyze the implications of the observed TeV characteristics and show that it proves challenging to account for them within conventional acceleration and emission models. We discuss a new pulsar-type scenario for the origin of variable, very high energy (VHE) emission close to the central supermassive black hole and show that magneto-centrifugally accelerated electrons could efficiently Compton upscatter sub-mm ADAF disk photons to the TeV regime, leading to VHE characteristics close to those observed. This suggests, conversely, that VHE observations of highly under-luminous AGNs could provide an important diagnostic tool for probing the conditions prevalent in the inner accretion disk of these sources.

scholarly journals Neutrino and γ-ray Emission from the Core of NGC1275 by Magnetic Reconnection: GRMHD Simulations and Radiative Transfer/Particle Calculations

2018 ◽  
Vol 14 (S342) ◽  
pp. 184-188
Author(s):  
J. C. Rodríguez-Ramírez ◽  
Elisabete M. de Gouveia Dal Pino ◽  
R. Alves Batista
Keyword(s):  
Monte Carlo ◽  
Radiative Transfer ◽  
Magnetic Reconnection ◽  
Neutrino Flux ◽  
Cosmic Ray ◽  
High Energy ◽  
Emission Model ◽  
The Core ◽  
Very High Energy ◽  
General Relativistic

AbstractVery high energy (VHE) emission has been detected from the radio galaxy NGC1275, establishing it as a potential cosmic-ray (CR) accelerator and a high energy neutrino source. We here study neutrino and γ-ray emission from the core of NGC1275 simulating the interactions of CRs assumed to be accelerated by magnetic reconnection, with the accreting plasma environment. To do this, we combine (i) numerical general relativistic (GR) magneto-hydrodynamics (MHD), (ii) Monte Carlo GR leptonic radiative transfer and, (iii) Monte Carlo interaction of CRs. A leptonic emission model that reproduces the SED in the [103-1010.5] eV energy range is used as the background target for photo-pion interactions+electromagnetic cascading. CRs injected with the power-law index κ=1.3 produce an emission profile that matches the VHE tail of NGC1275. The associated neutrino flux, below the IceCube limits, peaks at ∼PeV energies. However, coming from a single source, this neutrino flux may be an over-estimation.

scholarly journals Very High Energy Gamma-Ray Radiation from the Stellar Mass Black Hole Binary Cygnus X-1

2007 ◽  
Vol 665 (1) ◽  
pp. L51-L54 ◽  
Author(s):  
J. Albert ◽  
E. Aliu ◽  
H. Anderhub ◽  
P. Antoranz ◽  
A. Armada ◽  
...  
Keyword(s):  
Black Hole ◽  
Gamma Ray ◽  
High Energy ◽  
Stellar Mass ◽  
High Energy Gamma ◽  
Very High Energy ◽  
Energy Gamma ◽  
Black Hole Binary ◽  
Very High

scholarly journals OBSERVATIONS OF MICROQUASAR CANDIDATES WITH THE MAGIC TELESCOPE

2008 ◽  
Vol 17 (10) ◽  
pp. 1859-1866
Author(s):  
◽  
J. RICO
Keyword(s):  
Black Hole ◽  
Experimental Evidence ◽  
Energy Band ◽  
High Energy ◽  
Time Dependent ◽  
X Ray ◽  
Orbital Cycles ◽  
Very High Energy ◽  
Γ Ray ◽  
Very High

We report on the results from the observations in very high energy band (VHE, Eγ ≥ 100 GeV ) of the γ-ray binary LS I +61 303 and the black hole X-ray binary (BHXB) Cygnus X-1. LS I +61 303 was recently discovered at VHE by MAGIC1 and here we present the preliminary results from an extensive observation campaign, comprising 112 observation hours covering 4 orbital cycles, aiming at determining the time-dependent features of the VHE emission. Cygnus X-1 was observed for a total of 40 hours during 26 nights, spanning the period between June and November 2006. We report on the results of the searches for steady and variable γ-ray signals from Cygnus X-1, including the first experimental evidence for an intense flare, of duration between 1.5 and 24 hours.

scholarly journals Colliding-Wind Binaries as a Source of TeV Cosmic Rays

2021 ◽  
Vol 8 ◽  
Author(s):  
Grzegorz Kowal ◽  
Diego A. Falceta-Gonçalves
Keyword(s):  
Magnetic Field ◽  
Gamma Ray ◽  
Three Dimensional ◽  
Strong Shock ◽  
Compact Object ◽  
High Energy ◽  
Test Particles ◽  
Very High Energy ◽  
Magnetohydrodynamic Simulations ◽  
Very High

In addition to gamma-ray binaries which contain a compact object, high-energy and very high–energy gamma rays have also been detected from colliding-wind binaries. The collision of the winds produces two strong shock fronts, one for each wind, both surrounding a shock region of compressed and heated plasma, where particles are accelerated to very high energies. Magnetic field is also amplified in the shocked region on which the acceleration of particles greatly depends. In this work, we performed full three-dimensional magnetohydrodynamic simulations of colliding winds coupled to a code that evolves the kinematics of passive charged test particles subject to the plasma fluctuations. After the run of a large ensemble of test particles with initial thermal distributions, we show that such shocks produce a nonthermal population (nearly 1% of total particles) of few tens of GeVs up to few TeVs, depending on the initial magnetization level of the stellar winds. We were able to determine the loci of fastest acceleration, in the range of MeV/s to GeV/s, to be related to the turbulent plasma with amplified magnetic field of the shock. These results show that colliding-wind binaries are indeed able to produce a significant population of high-energy particles, in relatively short timescales, compared to the dynamical and diffusion timescales.

scholarly journals Very-high-energy Emission from Magnetic Reconnection in the Radiative-inefficient Accretion Flow of SgrA*

2019 ◽  
Vol 879 (1) ◽  
pp. 6 ◽  
Author(s):  
Juan Carlos Rodríguez-Ramírez ◽  
Elisabete M. de Gouveia Dal Pino ◽  
Rafael Alves Batista
Keyword(s):  
Magnetic Reconnection ◽  
High Energy ◽  
Accretion Flow ◽  
Energy Emission ◽  
Very High Energy ◽  
High Energy Emission ◽  
Very High

scholarly journals Rotationally driven VHE emission from the Vela pulsar

2019 ◽  
Vol 627 ◽  
pp. A22 ◽  
Author(s):  
Z. Osmanov ◽  
F. M. Rieger
Keyword(s):  
Particle Acceleration ◽  
Gamma Ray ◽  
Spectral Characteristics ◽  
High Energy ◽  
Radiation Mechanisms ◽  
Inverse Compton ◽  
Photon Index ◽  
Very High Energy ◽  
Vela Pulsar ◽  
Very High

Context. The recent detection of pulsed γ-ray emission from the Vela pulsar in the ∼10 to 100 GeV range by H.E.S.S. promises important potential to probe into the very high energy (VHE) radiation mechanisms of pulsars. Aims. A combined analysis of H.E.S.S. and Fermi-LAT data suggests that the leading wing of the P2 peak shows a new, hard gamma-ray component (with photon index as hard as Γ ∼ 3.5), setting in above 50 GeV and extending beyond 100 GeV. We study these findings in the context of rotationally driven (centrifugal) particle acceleration. Methods. We analyze achievable particle energies in the magnetosphere of the Vela pulsar and calculate the resultant emission properties. Results. Inverse Compton up-scattering of thermal photons from the surface of the star is shown to lead a pulsed VHE contribution reaching into the TeV regime with spectral characteristics compatible with current findings. If confirmed by further observations this could be the second case where rotationally driven processes turn out to be important to understand the VHE emission in young pulsars.

A FRACTAL-DISCRETE SCHEME FOR COSMIC PARTICLE ACCELERATION

2007 ◽  
Vol 16 (02n03) ◽  
pp. 521-526
Author(s):  
A. L. DOS SANTOS ◽  
L. P. L. DE OLIVEIRA ◽  
B. E. J. BODMANN ◽  
M. T. VILHENA
Keyword(s):  
Particle Acceleration ◽  
Energy Spectrum ◽  
Energy Range ◽  
Power Law ◽  
Cosmic Ray ◽  
High Energy ◽  
Cosmic Particle ◽  
Observational Fact ◽  
Very High Energy ◽  
Very High

The present article is an attempt to provide a parametrization for particle acceleration probabilities in the very high energy range combining a discrete fractal scheme for interaction probabilities and the observational fact of a power law energy spectrum for cosmic ray particles.

scholarly journals Acceleration of particles up to PeV energies at the galactic centre

2016 ◽  
Vol 12 (S324) ◽  
pp. 317-321
Author(s):  
Stefano Gabici ◽  
Felix A. Aharonian ◽  
Emmanuel Moulin ◽  
Aion Viana
Keyword(s):  
Black Hole ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Galactic Centre ◽  
Acceleration Of Particles ◽  
Supermassive Black Hole ◽  
Centre Region ◽  
Very High Energy ◽  
Sgr A ◽  
Very High

AbstractRecent very high energy observations of the galactic centre region performed by H.E.S.S. revealed the presence of a powerful PeVatron. This is the first of such objects detected, and its most plausible counterpart seems to be associated to Sgr A*, the supermassive black hole in the centre of our galaxy. The implications of this discovery will be discussed, in particular in the context of the problem of the origin of galactic cosmic rays.

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