Related papers: H.E.S.S. Observations of LS 5039
New observations of LS 5039, a High Mass X-ray Binary comprising a massive star and compact object, were carried out with the High Energy Stereoscopic System of Cherenkov Telescopes (H.E.S.S.) in 2005 at very high energy (VHE) gamma-ray…
LS 5039 is a gamma-ray binary system observed in a broad energy range, from radio to TeV energies. The binary system exhibits both flux and spectral modulation as a function of its orbital period. The X-ray and very-high-energy (VHE, E >…
Gamma-ray binaries are systems composed of a compact object orbiting a massive companion star. The interaction between these two objects can drive relativistic outflows, either jets or winds, in which particles can be accelerated to…
Several gamma-ray binaries have been recently detected by the High-Energy Stereoscopy Array (H.E.S.S.) and the Major Atmospheric Imaging Cerenkov (MAGIC) telescope. In two cases, their nature is unknown, since a final observational feature…
Gamma-ray emission in the TeV range has been detected by HESS from two X-ray binaries: PSR B1259-63 and LS 5039. In both, the early-type star provides large numbers of target photons for pair-production with TeV gamma-rays. This results in…
Gamma-ray binaries, composed of a massive star and compact object, have been established as a new class of sources of very high energy (VHE) photons. The gamma-rays are produced by inverse Compton scattering of the stellar light by VHE…
LS 5039 is a Galactic binary system emitting high and very-high energy gamma rays. The gamma-ray flux is modulated on the orbital period and the TeV lightcurve shaped by photon-photon annihilation. The observed very-high energy modulation…
Very high energy (VHE) gamma-rays have recently been detected from the Galactic black-hole candidate and microquasar LS 5039. A plausible site for the production of these VHE gamma-rays is the region close to the mildly relativistic…
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…
Recently, the $\gamma$-ray emission at MeV and GeV energies from the object LMC P3 in the Large Magellanic Cloud has been discovered to be modulated with a 10.3-days period, making it the first extra-galactic $\gamma$-ray binary. This work…
The results of gamma-ray observations of the binary system HESS J0632+057 collected during 450 hours over 15 years, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at…
Context. Recently, the high-energy (HE, 0.1-100 GeV) $\gamma$-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic…
LS 5039 is one of a handful of X-ray binaries that have been recently detected at high-energy $\gamma$-rays, in this case, by the High-Energy Stereoscopy Array (H.E.S.S.). The nature of this system is unknown: both a black hole and a pulsar…
We report the discovery of very-high-energy (VHE) gamma-ray emission of the binary system PSR B1259-63/SS 2883 of a radio pulsar orbiting a massive, luminous Be star in a highly eccentric orbit. The observations around the 2004 periastron…
The High Energy Stereoscopic System (H.E.S.S.) is a southern hemisphere array of four Imaging Atmospheric Cherenkov Telescopes observing the sky in the very high energy gamma-ray range (E $>$ 100 GeV). VHE observations are an invaluable…
HESS J0632+057 is the only gamma-ray binary known so far whose position in the sky allows observations with ground-based observatories both in the northern and southern hemispheres. Here we report on long-term observations of HESS J0632+057…
An extended observation campaign of the gamma-ray binary system PSR B1259$-$63 has been conducted with the H.E.S.S. (High Energy Stereoscopic System) II 5-telescope array during the system's periastron passage in 2014. We report on the…
Non-thermal variable emission from radio to very-high energy gamma rays (VHE; >100 GeV) are the prime characteristics of gamma-ray binaries. The underlying physical processes leading to the observed VHE emission are not well understood, as…
Context. Gamma-ray binaries are systems composed of a massive star and a compact object whose interaction leads to particle acceleration up to relativistic energies. In the last fifteen years, a few binaries have been discovered to emit at…
A detailed parameter study of the gamma-gamma absorption effects in LS 5039 is presented. For a range of plausible locations of the VHE gamma-ray emission region and the allowable range of viewing angles, the de-absorbed, intrinsic VHE…