相关论文: High-Energy Aspects of Astrophysical Jets
Constraints on the dynamics, dissipation, and production of VHE neutrinos in relativistic jets are derived using opacity calculations and VHE $\gamma$-ray observations. In particular, it is demonstrated how rapid variability of the…
Relativistic black-hole jet sources are leading candidates for high energy (>> TeV) neutrino production. The relations defining (a) efficient photopion losses of cosmic-ray protons on target photons and (b) gamma-gamma opacity of gamma rays…
Relativistic jets are one of the most powerful manifestations of the release of energy related to the supermassive black holes at the centre of active galactic nuclei (AGN). Their emission is observed across the entire electromagnetic…
We show that high-energy neutrinos can be efficiently produced in X-ray binaries with relativistic jets and high-mass primary stars. We consider a system where the star presents a dense equatorial wind and the jet has a small content of…
If the jets of microquasars carry a significant power in the form of relativistic hadrons, then gamma rays and neutrinos can be produced by interactions with matter and photon fields either external or internal to the jet. In this paper I…
Recent observations suggest that gamma ray bursts (GRBs) and their afterglows are produced in star formation regions in distant galaxies by highly relativistic jets that happen to point in our direction. Relativistic beaming collimates the…
A recent progress in the study of $\gamma$-ray jets is reviewed, with a focus on some theoretical interpretations of the VHE emission from M87, and possibly other misaligned blazars; the connection betwe en the GeV breaks exhibited by…
We discuss some phenomenological aspects of $\gamma$-ray emitting jets. In particular, we present calculations of the $\gamma$-sphere and $\pi$-sphere for various target photon fields, and employ them to demonstrate how $\gamma$-ray…
I review the current knowledge of high-energy emission from extragalctic jets. First I discuss gamma-ray emission from blazars, which provides us numerous precious information on the innermost portions of the relativistic jets. I describe…
Nature produces cosmic ray particles, probably protons, with energies well above $10^{20}$ eV -- how are they produced? Where do they come from? Gamma rays with energies above $10^{13}$ eV are produced in jets of active galaxies -- are…
The production of high-energy astrophysical neutrinos is tightly linked to the emission of hadronic gamma-rays. I will discuss the recent observation of TeV to PeV neutrinos by the IceCube Cherenkov telescope in the context of gamma-ray…
The Compton Gamma Ray Observatory revealed the high energy emission of some Active Galactic Nuclei called "Blazars"; few of them have also been observed by ground Cererenkov arrays. Those sources observed with Whipple Observatory emit gamma…
Blazars are thought to emit highly-collimated outflows, so-called jets. By their close alignment to our line of sight, relativistic beaming effects enable us to observe these jets over the whole electromagnetic spectrum up to TeV energies,…
The measured spectral energy distribution and variability time scale are used to determine the radiation and magnetic-field energy densities in the relativistic plasma that forms the gamma-ray emitting jet in the blazar 3C 279. Assuming…
Astrophysical models for the high-energy emission of blazars are reviewed. Blazars ejecting relativistic radio jets at small angles to the line-of-sight are the only type of active galactic nuclei (AGN) discovered above 100 MeV. The…
Supermassive black holes in the centers of galaxies are very common. They are known to rotate, accrete, spin down and eject highly relativistic jets; those jets pointed at us all seem to show a spectrum with two strong bumps, one in the TeV…
Blazars are a rare class of active galactic nuclei (AGN) with relativistic jets pointing towards the observer. Jets are thought to be launched as Poynting-flux dominated outflows that accelerate to relativistic speeds at the expense of the…
We propose a straightforward and efficient mechanism for the high-energy emission of relativistic astrophysical jets associated with an exchange of interacting high-energy photons between the jet and the external environment. Physical…
Microquasars, compact binary systems with an accreting stellar-mass black hole or neutron star, are promising candidates for high-energy particle acceleration. Recently, the LHAASO collaboration reported on the detection of $>100$ TeV…
We present a model for high-energy emission in microquasars where the energy content of the jets is dominated by relativistic protons. We also include a primary leptonic component. Particles are accelerated up to relativistic energies in a…