TAVECCHIO F.

Lately, a specific kind of blazars drew the attention of the gamma-ray astronomy community: the extreme TeV BL Lacs, blazars that present an extremely energetic and hard emission at very high-energy. Explaining their features is still an open challenge, in fact the most used phenomenological models have difficulties to satisfactorily reproduce...

Extreme BL Lacs (EHBL) form a subclass of blazars, which challenge standard emission scenarios. In a recent study it has been argued that their peculiar properties can be explained if emitting electrons are accelerated in a series of oblique shocks induced by the recollimation of the relativistic jet. However, new 3 D simulations of...

Blazars are potential neutrino emitters as suggested by the detection of a high-energy neutrino in the direction of the flaring Blazar TXS 0506+056, in 2017. However, the origin of neutrinos from this source is still unclear. This work aims at finding and characterizing other Blazars with similar features as TXS 0506+056. We selected sources...

Context. Extreme TeV BL Lacs are a class of blazars with unique spectral and temporal features that are not easily reproducible using standard one-zone models based on single shock acceleration. To account for their peculiar properties, we elaborated a two-step acceleration model in which a recollimation shock and the subsequent downstream...