Mildly relativistic, oblique shocks are generally considered to be among the most plausible sites of relativistic particle acceleration and the subsequent production of strongly variable, polarized multi-wavelength emission ...

Recent observations of distant gamma ray sources indicate that the universe may be more transparent to VHE-gamma-rays than expected. In this paper we study the reduction of the EBL gamma-gamma opacity due to the existence ...

Mildly relativistic, oblique shocks are frequently invoked as possible sites of relativistic particle acceleration and production of strongly variable, polarized multi-wavelength emission from relativistic jet sources ...

On the 28th of January, the High Energy Stereoscopic System (H.E.S.S. the world’s largest ground-based gamma-ray observatory, located in Namibia) detected an orphan TeV gamma-ray flare in 3C279, not accompanied by flaring ...

The Automatic Telescope for Optical Monitoring is a 75cm optical telescope located at the H.E.S.S. site in Namibia. Since 2005, it monitors around 250 gamma-ray emitting AGN and has observed numerous blazar flares in several ...

A large number of new “black widow” and “redback” energetic millisecond pulsars with irradiated stellar companions have been discovered through radio and optical searches of unidentified Fermi sources. Synchrotron emission, ...

A large number of new black widow and redback energetic millisecond pulsars with irradiated stellar companions have been discovered through radio searches of unidentified Fermi sources. We construct a 3D emission model ...

The spectral energy distributions (SEDs) and variability of astrophysical sources can be modeled in many different ways, in particular, the production of X-rays and γ-rays in the SEDs of blazars. High-energy polarimetry ...

The supermassive black holes in the centres of active galaxies (AGN) eject powerful relativistic jets which propagate over kpc scales, showing no significant momentum loss. Both observational evidence as well as theoretical ...

The flat spectrum radio quasar 4C +01.02 became one of the brightest active galactic nuclei detected at high redshift (z = 2.1) in gamma rays when it underwent a series of outbursts during several months in 2016. We monitored ...