Related papers: Gamma-ray flares from black hole coronae
Galactic black hole coronae are composed of a hot, magnetized plasma. The spectral energy distribution produced in this component of X-ray binaries can be strongly affected by different interactions between locally injected relativistic…
Accreting black holes in galactic X-ray sources are surrounded by hot plasma. The innermost part of these systems is likely a corona with different temperatures for ions and electrons. In the so-called low-hard state, hot electrons…
The X-ray and radio flares observed in X-ray binaries and active galactic nuclei (AGN) are attributed to energetic electrons in the plasma ejecta from the accretion flows near the black hole in these systems. It is argued that magnetic…
We present a model for neutrino flares in accreting black holes based on the injection of a non-thermal population of relativistic particles in a magnetized corona. The most important products of hadronic and photohadronic interactions at…
We develop a model of particle energization and emission from strongly turbulent black-hole coronae. Our local model is based on a set of 2D radiative particle-in-cell simulations with an electron-ion plasma composition, injection and…
Using a Monte Carlo ray-tracing code in full general relativity, we calculate the transport of photons from a geodesic hot spot emitter through a corona of hot electrons surrounding a black hole. Each photon is followed until it is either…
The high-energy emission ($400$ keV $- 2$ MeV) of Cygnus X-1 --the most well-studied Galactic black hole-- was recently found to be strongly polarized. The origin of this radiation is still unknown. In this work, we suggest that it is the…
Context. Many low-redshift active galactic nuclei harbor a supermassive black hole accreting matter at low or medium rates. At such rates, the accretion flow usually consists of a cold optically thick disk, plus a hot, low density,…
The corona is a key component of most luminous accreting black holes, carrying 5 - 30 % of the power and in non-jetted Active Galactic Nuclei (AGN), creating all the X-ray emission above $\simeq 1-2$ keV. Its emission illuminates the inner…
Using a non-linear Monte-Carlo code we investigate the radiative response of an accretion disk corona system to static homogeneous flares. We model a flare by a rapid (comparable to the light crossing time) energy dissipation in the corona…
In the inner regions of an accretion disk around a black hole, relativistic protons can interact with ambient matter to produce electrons, positrons and $\gamma$-rays. The resultant steady state electron and positron particle distributions…
With mass ratio larger than $\sim 5$ (which depends on the black hole spin and the star radius), star disruption is not expected for a black hole merging with a neutron star during the final plunge phase. In the late inspiral stage, the…
We present time-dependent simulations of a two-phase accretion flow around a black hole. The accretion flow initially is composed of an optically thick and cool disc close to the midplane, while on top and below the disc there is a hot and…
We present a convariant formulation for radiative transfer in curved space time and demonstrate some applications in the black-hole systems. We calculate the emission from semi-transparent accretion tori around black holes, for opacity…
In the inner regions of an accretion disk around a black hole, the presence of non-thermal protons would via p-p collisions produce electrons, positrons and $\gamma$-rays. For such a scenario, the steady state electron-positron distribution…
Data derived from general relativistic magnetohydrodynamic simulations of accretion onto black holes can be used as input to a postprocessing scheme that predicts the radiated spectrum. Combining a relativistic Compton scattering radiation…
Accreting sources such as AGN, X-ray binaries or gamma-ray bursts are known to be strong, high energy emitters. The hard emission is though to originate from plasmas of thermal and/or non-thermal high energy particles. Not only does this…
Stellar-mass black holes in x-ray binary systems are powered by mass transfer from a companion star. The accreted gas forms an accretion disk around the black hole and emits x-ray radiation in two distinct modes: hard and soft state. The…
Supermassive black holes are believed to be the central power house of active galactic nuclei. Applying the pulsar outer-magnetospheric particle accelerator theory to black-hole magnetospheres, we demonstrate that an electric field is…
The emphasis of observational and theoretical flare studies in the last decade or two has been on the flare corona, and attention has shifted substantially away from the flare's chromospheric aspects. However, although the pre-flare energy…