scholarly journals Radiation GRMHD simulations of M87: Funnel properties and prospects for gap acceleration

2021 ◽  
Author(s):  
Philippe Z Yao ◽  
Jason Dexter ◽  
Alexander Y Chen ◽  
Benjamin R Ryan ◽  
George N Wong
Keyword(s):  
Black Hole ◽  
Radiation Field ◽  
Gamma Ray ◽  
Theoretical Models ◽  
High Energy ◽  
Point Sources ◽  
Photon Momentum ◽  
Very High Energy ◽  
Order Of Magnitude ◽  
General Relativistic

Abstract We use the public code ebhlight to carry out 3D radiative general relativistic magnetohydrodynamics (GRMHD) simulations of accretion on to the supermassive black hole in M87. The simulations self-consistently evolve a frequency-dependent Monte Carlo description of the radiation field produced by the accretion flow. We explore two limits of accumulated magnetic flux at the black hole (SANE and MAD), each coupled to several sub-grid prescriptions for electron heating that are motivated by models of turbulence and magnetic reconnection. We present convergence studies for the radiation field and study its properties. We find that the near-horizon photon energy density is an order of magnitude higher than is predicted by simple isotropic estimates from the observed luminosity. The radially dependent photon momentum distribution is anisotropic and can be modeled by a set of point-sources near the equatorial plane. We draw properties of the radiation and magnetic field from the simulation and feed them into an analytic model of gap acceleration to estimate the very high energy (VHE) gamma-ray luminosity from the magnetized jet funnel, assuming that a gap is able to form. We find luminosities of $\rm \sim 10^{41} \, erg \, s^{-1}$ for MAD models and $\rm \sim 2\times 10^{40} \, erg \, s^{-1}$ for SANE models, which are comparable to measurements of M87’s VHE flares. The time-dependence seen in our calculations is insufficient to explain the flaring behaviour. Our results provide a step towards bridging theoretical models of near-horizon properties seen in black hole images with the VHE activity of M87.

scholarly journals GAMMA RAY BURSTS AND PARTICLE PHYSICS

1995 ◽  
Vol 10 (38) ◽  
pp. 2897-2913
Author(s):  
DAVID B. CLINE
Keyword(s):  
Black Hole ◽  
Particle Physics ◽  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Primordial Black Hole ◽  
Black Hole Evaporation ◽  
Very High Energy ◽  
Fine Time ◽  
Made In

We provide a brief review of the current situation concerning gamma ray bursts, with emphasis on the role that particle physics may play in the interesting phenomena. The current understanding of GRB origins allows for a large range of physical processes from primordial black hole evaporation to neutron star and black hole collisions. There does not seem to be a simple standard luminosity function and the burst times range from ms to 1000 s of seconds five orders of magnitude. It is likely that some type of fireball model is needed to explain the GRBs. No counterparts of GRB have been detected. We indicate some ways in which progress can be made in either the study of the fine time structure (~μs) or the detection of very high energy photons (>100 GeV to >100 TeV). We also indicate how a small but unique class of the GRB could come from primordial black hole evaporation.

Future prospects for y-ray astronomy

1981 ◽  
Vol 301 (1462) ◽  
pp. 693-701 ◽  
Keyword(s):  
Gamma Ray ◽  
Dynamic Pressure ◽  
High Energy ◽  
Compact Objects ◽  
Pressure Effects ◽  
Very High Energy ◽  
Order Of Magnitude ◽  
High Energy Particles ◽  
Nuclear Processes ◽  
The Universe

As y-ray astronomy moves from the discovery to the exploratory phase, the promise of y-ray astrophysics noted by theorists in the late 1940s and 1950s is beginning to be realized. In the future, satellites should carry instruments that will have over an order of magnitude greater sensitivity than those flown thus far, and, for at least some portions of the y-ray energy range, these detectors will also have substantially improved energy and angular resolution. The information to be obtained from these experiments should greatly enhance our knowledge of several astrophysical phenomena including the very energetic and nuclear processes associated with compact objects, astrophysical nucleosynthesis, solar particle acceleration, the chemical composition of the planets and other bodies of the Solar System, the structure of our Galaxy, the origin and dynamic pressure effects of the cosmic rays, high energy particles and energetic processes in other galaxies especially active ones, and the degree of matter-antimatter symmetry of the Universe. The y-ray results of the forthcoming programs such as Gamma-I, the Gamma Ray Observatory, the y-ray burst network, Solar Polar, and very high energy y-ray telescopes on the ground will almost certainly provide justification for more sophisticated telescopes. These advanced instruments might be placed on the Space Platform currently under study by N.A.S.A.

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 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 The Galactic Center Region Imaged by VERITAS from 2010{2012

2014 ◽  
Vol 1 (1) ◽  
pp. 227-230
Author(s):  
Matthias Beilicke
Keyword(s):  
Supernova Remnant ◽  
Gamma Ray ◽  
Galactic Center ◽  
Region Of Interest ◽  
High Energy ◽  
Central Black Hole ◽  
Potential Sources ◽  
Very High Energy ◽  
Order Of Magnitude ◽  
Very High

The galactic center has long been a region of interest for high-energy and very-high-energy observations. Many potential sources of GeV/TeV gamma-ray emission are located in this region, e.g. the accretion of matter onto the central black hole, cosmic rays from a nearby shell-type supernova remnant, or the annihilation of dark matter. The galactic center has been detected at MeV/GeV energies by EGRET and recently by <em>Fermi</em>/LAT. At TeV energies, the galactic center was detected at the level of 4 standard deviations with the Whipple 10m telescope and with one order of magnitude better sensitivity by H.E.S.S. and MAGIC. We present the results from 3 years of VERITAS galactic center observations conducted at large zenith angles. The results are compared to astrophysical models.

scholarly journals PROBING THE CENTRAL BLACK HOLE IN M87 WITH GAMMA-RAYS

2012 ◽  
Vol 27 (28) ◽  
pp. 1230030 ◽  
Author(s):  
FRANK M. RIEGER ◽  
FELIX AHARONIAN
Keyword(s):  
Black Hole ◽  
Large Scale ◽  
Gamma Ray ◽  
High Sensitivity ◽  
High Energy ◽  
X Rays ◽  
Central Black Hole ◽  
Central Engine ◽  
Very High Energy ◽  
Observational Status

Recent high-sensitivity observation of the nearby radio galaxy M87 has provided important insights into the central engine that drives the large-scale outflows seen in radio, optical and X-rays. This review summarizes the observational status achieved in the high energy (HE < 100 GeV) and very high energy (VHE > 100 GeV) gamma-ray domains, and discusses the theoretical progress in understanding the physical origin of this emission and its relation to the activity of the central black hole.

scholarly journals The capture of main sequence stars and giant stars by a massive black hole

2006 ◽  
Vol 2 (S238) ◽  
pp. 403-404
Author(s):  
Y. Lu ◽  
Y. F Huang ◽  
Z. Zheng ◽  
S. N. Zhang
Keyword(s):  
Black Hole ◽  
Gamma Rays ◽  
Main Sequence ◽  
Gamma Ray ◽  
High Energy ◽  
Main Sequence Stars ◽  
Massive Black Hole ◽  
Giant Stars ◽  
Very High Energy ◽  
Very High

AbstractSince the mass-radius relation is quite different for a main sequence (MS) star and a giant (G) star, we find that the radiation efficiencies in the star capture processes by a black hole (BH) are also very different. This may provide a useful way to distinguish the capture of MS and G stars. Comparing with observations of the very high energy (VHE) gamma-ray emissions, we argue the event that triggers the gamma-ray emission in the energy range 4–40 TeV should be a G star capture. On the other hand, the capture of MS stars by the massive BH is required when the measured spectrum of VHE gamma-rays extends from 109 to 1015 eV.

VERY HIGH ENERGY GAMMA-RAY MEASUREMENTS OF BLAZARS

2008 ◽  
Vol 17 (09) ◽  
pp. 1431-1441
Author(s):  
BERRIE GIEBELS
Keyword(s):  
Black Hole ◽  
Gamma Ray ◽  
High Energy ◽  
The Status ◽  
Relativistic Flow ◽  
Very High Energy ◽  
Acceleration Zone ◽  
Energy Gamma ◽  
Γ Rays ◽  
Very High

The origin of γ-rays emitted by blazars is widely attributed to radiative cooling of the most energetic particles in a relativistic flow, which itself is thought to originate from the surroundings of a supermassive black hole. The linkage between the accreting gas, the black hole, jet formation, and the observed radiation from the jet, are still very difficult to establish. The most energetic γ-rays are likely to be produced close to the comptonizing particles acceleration zone, and are therefore a unique probe of the underlying physical mechanisms at play. This report contains a review of the status of the field of Very High Energy (VHE) γ-ray astronomy, in the light of measurements from the current generation of Atmospheric Čerenkov Telescopes (ACTs), which have dramatically changed our view of blazars over the last years, and given us new insights about the blazar phenomenon.

scholarly journals A Large-Area Gas-Čerenkov Detector for High-Energy Gamma-Ray Astronomy

1971 ◽  
Vol 41 ◽  
pp. 75-76 ◽  
Author(s):  
J. Delvaille ◽  
K. Greisen ◽  
D. Koch ◽  
B. McBreen ◽  
G. Fazio ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Point Sources ◽  
Large Area ◽  
Cerenkov Detector ◽  
High Energy Gamma ◽  
Area 5 ◽  
Theoretical Predictions ◽  
Order Of Magnitude ◽  
Energy Gamma

Experimental upper limits of the high-energy gamma-ray flux (above 100 MeV) from point sources are about 10−5 cm−2 s−1, and realistic theoretical predictions for the strongest sources are an order of magnitude lower than this, while the diffuse background flux is about 4 × 10−5 cm−2 s−1 sr−1 in space, and 100 times higher at balloon altitudes. To meet the need for instrumental sensitivity and angular resolution adequate to measure the small but important gamma-ray source strengths, a telescope of large area (5 m2) and fine angular discrimination (0.5 deg at 300 MeV, 0.3 deg at energies above 1 GeV) has been developed.

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