Discovery of very high energy gamma-ray emission coincident with molecular clouds in the W28 (G6.4-0.1) field
We observed the W28 field (for ~40 h) at Very High Energy (VHE) gamma-ray energies (E>0.1 TeV) with the H.E.S.S. Cherenkov telescopes. A reanalysis of EGRET E>100 MeV data was also undertaken. Results from…
Discovery of VHE gamma-rays from the high-frequency-peaked BL Lac object RGB J0152+017
Aims: The BL Lac object RGB J0152+017 (z=0.080) was predicted to be a very high-energy (VHE; > 100 GeV) gamma-ray source, due to its high X-ray and radio fluxes. Our aim is to understand…
Upper Limits from HESS AGN Observations in 2005-2007
AIMS: Very high energy (VHE; E>100 GeV) gamma-ray studies were performed for 18 active galactic nuclei (AGN) from a variety of AGN classes.METHODS: VHE observations of a sample of 14 AGN, considered candidate VHE…
HESS Observations and VLT Spectroscopy of PG 1553+113
AIMS: The properties of the very high energy (VHE; E>100 GeV) gamma-ray emission from the high-frequency peaked BL Lac PG 1553+113 are investigated. An attempt is made to measure the currently unknown redshift of…
H.E.S.S. VHE gamma-ray sources without identified counterparts
The detection of gamma rays in the very-high-energy (VHE) energy range (100 GeV–100 TeV) provides a direct view of the parent population of ultra-relativistic particles found in astrophysical sources. For this reason, VHE gamma…
Observations of the Sagittarius Dwarf galaxy by the H.E.S.S. experiment and search for a Dark Matter signal
Observations of the Sagittarius dwarf spheroidal (Sgr dSph) galaxy were carried out with the H.E.S.S. array of four imaging air Cherenkov telescopes in June 2006. A total of 11 hours of high quality data…
Primary particle acceleration above 100 TeV in the shell-type supernova remnant RX J1713.7-3946 with deep H.E.S.S. observations
We present deep H.E.S.S. observations of the supernova remnant (SNR) RX J1713.7-3946. Combining data of three years – from 2003 to 2005 – we obtain significantly increased statistics and energy coverage as compared to…
New constraints on the Mid-IR EBL from the HESS discovery of VHE gamma rays from 1ES 0229+200
AIMS: To investigate the very high energy (VHE: >100 GeV) gamma-ray emission from the high-frequency peaked BL Lac 1ES 0229+200.METHODS: Observations of 1ES 0229+200 at energies above 580 GeV were performed with the High…
Discovery of VHE gamma-rays from the distant BL Lac 1ES 0347-121
Aims: Our aim is to study the production mechanism for very-high-energy (VHE; >100GeV) gamma-rays in distant active galactic nuclei (AGN) and use the observed VHE spectrum to derive limits on the Extragalactic Background Light…
An exceptional VHE gamma-ray flare of PKS 2155-304
The high-frequency peaked BL Lac PKS 2155-304 at redshift z=0.116 is a well-known VHE (>100 GeV) gamma-ray emitter. Since 2002 its VHE flux has been monitored using the H.E.S.S. stereoscopic array of imaging atmospheric-Cherenkov…
