Related papers: Lightning black holes as unidentified TeV sources
The current detectors of gamma-ray emission specially at TeV energies have too poor resolution to determine whether this emission is produced in the jet or in the core, particularly of low luminous, non-blazar AGNs (like radio galaxies). In…
We consider a compact binary system in which a Wolf-Rayet star supplies matter onto a stellar mass black hole or a neutron star. This matter forms an accretion disk which ejects a jet as observed in Galactic microquasars. A part of the jet…
TeV gravity models provide a scenario for black hole formation at energies much smaller than G_N^(-1/2) \sim 10^19 GeV. In particular, the collision of a ultrahigh energy cosmic ray with a dark matter particle in our galactic halo or with…
Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry, but still suffer from insufficient angular…
We estimate the TeV gamma-ray fluxes expected from the population of young pulsars in terms of the self-consistent time dependent hadronic-leptonic model for the high energy processes inside the pulsar wind nebulae. This radiation model…
We search for the gamma-ray counterparts of stellar-mass black holes using long-term Fermi archive to investigate the electrostatic acceleration of electrons and positrons in the vicinity of the event horizon, by applying the pulsar…
The central parsec of the Galaxy contains dozens of massive stars with a cumulative mass loss rate of ~ 10^{-3} solar masses per year. Shocks among these stellar winds produce the hot plasma that pervades the central part of the galaxy. We…
The total cosmic ray electron spectrum (electrons plus positrons) exhibits a break at a particle energy of $\sim 1\rm~TeV$ and extends without any attenuation up to $\rm \sim 20~ TeV $. Synchrotron and inverse Compton energy losses strongly…
Jets associated with Active Galactic Nuclei (AGN) have been observed for almost a century, initially at optical and radio wavelengths. They are now widely accepted as "exhausts" produced electromagnetically by the central, spinning, massive…
Low Luminosity Active Galactic Nuclei (LLAGNs) possess the characteristic features of more luminous Active Galactic Nuclei (AGNs) but exhibit a much lower nuclear Halpha luminosity than their more luminous counterparts. M87 (NGC 4486) and…
We study the structure of an outer-magnetospheric gap around a rotating neutron star. Migratory electrons and positrons are accelerated by the electric field exerted in the gap and radiate copious gamma-rays via curvature process. Some of…
TeV Halos, extended regions of TeV gamma-ray emission around middle-aged pulsars, have recently been established as a new source class in gamma-ray astronomy. These halos have been attributed to relativistic electrons and positrons that…
MeV blazars are the most luminous persistent sources in the Universe and emit most of their energy in the MeV band. These objects display very large jet powers and accretion luminosities and are known to host black holes with a mass often…
The LHAASO Collaboration has recently reported a measurement of the diffuse gamma-ray emission from the Galactic Plane at energies between 10 TeV and 1 PeV. While this emission is brighter than that expected from cosmic-ray interactions in…
Most accreting black holes emit a substantial fraction of their luminosity in hard X-rays/soft $\gamma$-rays of up to $\sim{\rm few}\times100$ keV. The observations suggest that the radiating gas is very hot, $T>10^9$ K, and optically thin.…
Milagro and HAWC have detected extended TeV gamma-ray emission around nearby pulsar wind nebulae (PWNe). Building on these discoveries, Linden et al. [1] identified a new source class -- TeV halos -- powered by the interactions of…
A fraction of AGN producing VHE gamma-rays are located in galaxy clusters. The magnetic field present in the intra-cluster medium would lead to conversions of VHE photons into axion-like particles (ALPs), which are a generic prediction of…
We have developed a model for gamma ray emission in jets of active galactic nuclei in which particle acceleration takes place at a shock in the relativistic jet plasma due to a massive star in the central region of the host galaxy moving…
Observations of very-high-energy (VHE) gamma-ray emission from supernova remnants (SNR) established them as sources of accelerated particles up to energies of 100 TeV. The dominant process - leptonic or hadronic - responsible for the VHE…
A gamma-ray burst (GRB) jet running into an external medium is expected to generate luminous GeV-TeV emission lasting from minutes to several hours. The high-energy emission results from inverse Compton upscattering of prompt and afterglow…