Observations of TeV binary systems with the H.E.S.S. telescope

TL;DR

This paper reports recent H.E.S.S. observations of gamma-ray binary systems, revealing both confirmations of previous models and unexpected findings, thus advancing understanding of relativistic outflows and gamma-ray emission mechanisms.

Contribution

It provides new observational data on multiple gamma-ray binaries, highlighting uncorrelated high-energy emissions and challenging existing emission models.

Findings

Confirmation of previous predictions for studied sources

Detection of uncorrelated GeV and TeV emissions in some systems

Unexpected results prompting new theoretical considerations

Abstract

Recent observations of binary systems obtained with the H.E.S.S. telescopes are providing crucial information on the physics of relativistic outflows and the engines powering them. We report here on new H.E.S.S. results on HESS J0632+057, PSR B1259-63/LS 2883, Eta Carinae and the recently discovered source HESS J1018-589. Despite the high-quality data obtained in the last years through both ground and space-based gamma-ray detectors, many questions on the mechanisms that permit binary systems to emit at gamma-rays remain open. In particular, it is becoming apparent that emission at high and very-high energies is uncorrelated in some gamma-ray binary systems, with bright GeV flares not observed at TeV energies (e.g. PSR B1259-63), and sources periodically detected at VHEs which are lacking its HE counterpart (e.g. HESS J0632+057). Our results mainly confirm the predictions derived previously for the studied sources, but unexpected results are also found in a few cases, which are discussed in the context of contemporaneous observations at lower energies.