Related papers: Blazars
We consider the acceleration of energetic particles by Fermi processes (i.e., diffusive shock acceleration, second order Fermi acceleration, and gradual shear acceleration) in relativistic astrophysical jets, with particular attention given…
Blazars radiate from relativistic plasma jets with bulk Lorentz factors {\Gamma} ~ 10, closely aligned along our line of sight. In a number of blazars of the Flat Spectrum Radio Quasar type such as 3C 454.3 and 3C 279 gamma-ray flares have…
Blazars are characterized by large amplitude and fast variability, indicating that the electron distribution is rapidly changing, often on time scales shorter than the light crossing time. We study the time dependent behavior of the…
The gamma-ray emission of blazar jets shows a pronounced variability and this feature provides limits to the size and to the speed of the emitting region. We study the gamma-ray variability of bright blazars using data from the first 18…
The phenomenological energy dissipation in QCD jets evolution with colour coherence is considered and the corresponding modified parton multiplicity and distribution function are computed.
We discuss the phenomenology of jet physics at hadron colliders, concentrating on the internal structure of jets, which is studied using the jet shape distribution or subjet distributions.
Blazars display strong variability on multiple timescales and in multiple radiation bands. Their variability is often characterized by power spectral densities (PSDs) and time lags plotted as functions of the Fourier frequency. We develop a…
The standard blazar paradigm consists of a supermassive black hole that expels relativistic jets of magnetized plasma in our direction. This plasma entrains nonthermal synchrotron-emitting electrons that furthermore scatter…
We describe a scenario to explain blazar periodicities with timescales of $\sim$ few years. The scenario is based on a binary super-massive black hole (SMBH) system in which one of the two SMBH carries a jet. We discuss the various…
BeppoSAX is best known for its role in the disclosure of the Gamma-Ray Burst mystery, but it has also improved our understanding of jetted sources in general, and blazars in particular. On the interpretational side, we are curious to see if…
Variability can be the pathway to understanding the physical processes in astrophysical jets, however, the high-cadence observations required to test particle acceleration models are still missing. Here we report on the first attempt to…
Recently reported coincidences between high-energy neutrino events and major blazar outbursts reinforce the relevance of lepto-hadronic emission models for blazars. We study the influence of physical parameters on the neutrino output…
X-ray polarimetry promises us an unprecedented look at the structure of magnetic fields and on the processes at the base of acceleration of particles up to ultrarelativistic energies in relativistic jets. Crucial pieces of information are…
Flux distribution is an important tool to understand the variability processes in active galactic nuclei. We now have available a great deal of observational evidences pointing towards the presence of log-normal components in the high…
Blazars, a class of active galaxies whose jets are relativistic and collimated flows of plasma directed along the line of sight and are prone to a slew of magneto-hydrodynamic (MHD) instabilities. We aim to study the interplay of radiation…
The paper is devoted to the prospects of using the laser radiation interaction with plasmas in the laboratory relativistic astrophysics context. We discuss the dimensionless parameters characterizing the processes in the laser and…
We present an internal shocks model to investigate particle acceleration and radiation production in microquasar jets. The jet is modelled with discrete ejecta at various time intervals. These ejecta (or 'shells') may have different…
Two-imcompressible phase model of star is briefly revised. Effects of rotation and general relativity are considered.
Blazars, a unique class of active galactic nuclei, exhibit highly variable emission across the electromagnetic spectrum. This variability frequently manifests as intense flaring events, sparking an ongoing debate in recent literature about…
The development of instabilities leading to the formation of internal shocks is expected in the relativistic outflows of both gamma-ray bursts and blazars. The shocks heat the expanding ejecta, generate a tangled magnetic field and…