Observations of binary systems with the H.E.S.S. telescopes

Abstract

Abstract. Observations of binary systems obtained recently with the High Energy Stereoscopic System (H.E.S.S) of Cherenkov telescopes are reported. The outcomes of a detailed observation campaign on PSR B1259-63 during its periastron passage in 2014 will be presented. This system was observed for the first time with H.E.S.S. II, providing spectra and light curves down to 200 GeV, which will be compared with observations conducted during previous periastron passages and with results from an analysis of contemporaneously taken Fermi-LAT data. Also long-term observations of LS 5039 with H.E.S.S in phase I and phase II are reported. This source was monitored at very high energies (VHEs) in a period of time spanning more than ten years. Its spectral energy distribution measured with H.E.S.S. II extends down to 120 GeV. Spectral results from the Fermi-LAT observations are shown as well, and the compatibility with H.E.S.S. results in the overlapping energy range is discussed. The identification of the new gamma-ray binary candidate HESS J1832-093 will also be presented. Furthermore, the search for VHE emission from the microquasars GRS 1915+105, Circinus X-1 and V4641 Sgr based on data from H.E.S.S. observations conducted contemporaneously with the RXTE satellite experiment will be reported. These data provide constraints on the integral gamma-ray flux at different X-ray states of the three sources.

Modelling the interaction between relativistic and non-relativistic winds in binary pulsar systems: strong magnetization of the pulsar wind

“…Several binary systems, e.g., PSR B1259−63/LS2883 (PSR B1259), LS 5039, 1FGL J1018.6−5856, LSI+61 • 303, and LMC P3 emit bright non-thermal emission that spans across the entire electromagnetic spectrum, from radio to gamma-ray energies (see, e.g., Dubus 2013, and references theirin). These systems are detected with ground-based Cherenkov detectors, H.E.S.S., MAGIC, and Veritas in the very-high-energy (VHE) regime and with the Fermi Large Area Telescope (Fermi LAT) at high energies (HE) (see, e.g., Corbet et al 2016Corbet et al , 2019Bordas et al 2017;Maier & VERI-TAS Collaboration 2017;López-Oramas et al 2018, and references therein). The spectral maximum typically appears at MeV-GeV energies.…”

A First Look at Periodicity in HAWC with TeV Binaries

“…LS 5039 is a high-mass X-ray binary system composed of a massive O-type star (M = 23M ) and a compact object (M = 3.7M ) with an orbital period of 3.9 days [2]. The nature of the compact companion is unknown.…”