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Aims. The BL Lac object RGB J0152+017 (z = 0.080) was predicted to be a very high-energy (VHE; > 100 GeV) γ-ray source, due to its high X-ray and radio fluxes. Our aim is to understand the radiative processes by investigating the observed emission and its production mechanism using the High Energy Stereoscopic System (H.E.S.S.) experiment. Methods. We(More)
In the past few decades, several models have predicted an energy dependence of the speed of light in the context of quantum gravity. For cosmological sources such as active galaxies, this minuscule effect can add up to measurable photon-energy dependent time lags. In this Letter a search for such time lags during the High Energy Stereoscopic System(More)
The Research Patient Data Repository (RPDR) is a clinical data registry that gathers medical records from various hospital systems and stores them centrally in one data warehouse. Research investigators can obtain aggregate total of patients that meet specific query criteria and can obtain patient identifiers and complete electronic medical records through(More)
The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we(More)
The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3 − 6) × 10 9 M) provides a unique opportunity to investigate the origin of very high energy (VHE; E>100 GeV) γ-ray emission generated in relativistic outflows and the surroundings of super-massive black holes. M 87 has been established as a VHE γ-ray emitter(More)
Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of approximately 10(15) electron volts. We report the detection of gamma rays--tracers of such cosmic rays--from the starburst galaxy NGC 253 using the High Energy Stereoscopic System(More)
Aims. Galaxy clusters are key targets in the search for ultra high energy particle accelerators. The Coma cluster represents one of the best candidates for such a search owing to its high mass, proximity, and the established non-thermal radio emission centred on the cluster core. Methods. The H.E.S.S. (High Energy Stereoscopic System) telescopes observed(More)
Aims. Our aim is to study the production mechanism for very-high-energy (VHE; >100 GeV) γ-rays in distant active galactic nuclei (AGN) and use the observed VHE spectrum to derive limits on the Extragalactic Background Light (EBL). We also want to determine physical quantities through the modeling of the object's broad-band spectral energy distribution(More)
Title Medical certification of work absence due to pain. A qualitative study of General Practitioners' and chronic pain patients' beliefs about the negotiated process of 'sick-listing'. Abstract Many people absent from employment due to ill health would have better outcomes by working. Attempting to reduce sickness absence, the UK government is promoting(More)