Speaker
Description
The galactic microquasar SS 433 has been extensively studied across the years, as it presents a unique opportunity to understand jet dynamics thanks to its proximity to Earth, at an estimated distance of ~ 5.5 kpc. The HAWC observatory in 2018 purported very-high-energy (VHE) emission associated to the SS 433 system, indicating that the energetic particles producing the X-ray emission of the outer jets may also be producing VHE gamma rays. The High Energy Stereoscopic System (H.E.S.S.) has discovered, in 2024, emission from the two jets in TeV ranges, revealing an energy-dependent morphology, consistent with X-ray observations. Later results that year from the LHAASO experiment at > 100 TeV, broaden the picture we have of the binary system in the overall gamma-ray band. Thus yielded observables within the high-, very-high-, ultra-high-energy gamma-ray ranges point to a multi-zone model to explain the emission components from this microquasar. In this presentation, I will focus on the SS 433 system and how the spatially-resolved VHE emission highlights a dominant leptonic origin at the multi-TeV energy band. Moreover, indications of the jet flow decelerating abruptly, in addition to evidence of highly efficient acceleration located in the outer jets, suggest the presence of strong shocks at a distance of ~25 pc, either side of the central binary system. Finally I will contextualise our past findings on how they probe this (new) class of gamma-ray sources and how they may enhance our understanding of powerful relativistic jets.