Gamma-ray constraints on heavy axion-like-particle decays from Fermi-LAT and H.E.S.S. blazar spectra
The propagation of very-high-energy (VHE; Eγ ≥ 100 GeV) gamma rays from extragalactic sources is affected by interactions with photons of the extragalactic background light (EBL), resulting in pair production that attenuates the intrinsic…
Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation with the H.E.S.S. Inner Galaxy Survey
Spectral gamma-ray line features are expected as key signatures from dark matter (DM) annihilations of TeV-scale particle DM. Observations of the Galactic Center with atmospheric Cherenkov telescopes are unique to probe thermal-relic TeV particle…
H.E.S.S. observations of composite Seyfert–starburst galaxies
Context. Composite galaxies that contain both Seyfert and starburst components may produce very high-energy (VHE; > 100 GeV) γ-ray emission at a wide range of spatial scales, from a few Schwarzschild radii of a…
Search for long-term variability of HESS J1745–290
At the center of our Galaxy lies the bright γ-ray point-like source HESS J1745-290, which is compatible in position with Sgr A⋆, although an association between the two remains uncertain. Using data obtained between…
Scrutinizing the 2020 multiwavelength outburst of PKS 0903–57 through observations with H.E.S.S.
The blazar PKS 0903–57 has recently been classified as a flat spectrum radio quasar at a redshift of z=0.2621. In March and April 2020, Fermi-LAT and AGILE reported tremendous activity in high-energy γ rays…
H.E.S.S. detection of the PSR J0855−4644 nebula
Context. HESS J0852−463 is a TeV γ-ray source located in the Galactic plane. The region consists of a supernova remnant (SNR, RX J0852.0−4622) with a shell-like morphology, commonly referred to as Vela Junior, and…
The second H.E.S.S. gamma-ray burst catalogue: 15 years of observations with the H.E.S.S. telescopes
Context. Recent observational efforts using imaging atmospheric Cherenkov telescopes (IACTs) have led to firm detections of very-high-energy (VHE) signals from bright gamma-ray bursts (GRBs), often at moderate redshifts. Aims. This work presents 15 years…
Combined dark matter search towards dwarf spheroidal galaxies with Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS
Dwarf spheroidal galaxies (dSphs) are excellent targets for indirect dark matter (DM) searches using gamma-ray telescopes because they are thought to have high DM content and a low astrophysical background. The sensitivity of these…
H.E.S.S. detection and multi-wavelength study of the z∼1 blazar PKS 0346–27
Context. PKS 0346-27 is a low synchrotron peaked blazar at redshift 0.991. The very high energy (VHE; E > 100 GeV) spectra of blazars are always affected by γγ absorption by the extragalactic background light (EBL),…
Constraining the nature of the most extreme Galactic particle accelerator: H.E.S.S. observations of the microquasar V4641 Sgr
Context. Microquasars have emerged as promising candidates to explain the cosmic-ray flux at petaelectronvolt energies. LHAASO observations revealed V4641 Sgr as the most extreme example so far. Its gamma-ray spectrum extends up to 800…
