Related papers: Characteristics of the Multi-Telescope Coincidence…
H.E.S.S. -- The High Energy Stereoscopic System-- is a new system of large atmospheric Cherenkov telescopes for GeV/TeV Gamma-ray astronomy. This paper describes the trigger system of H.E.S.S. with emphasis on the multi-telescope array…
The HEGRA system of Imaging Atmospheric Cherenkov Telescopes (IACTs) detects Cherenkov light produced by air showers. The concept of stereoscopic observation with the five HEGRA telescopes allows the reconstruction of various shower…
A fast trigger system is being designed as a potential upgrade to VERITAS, or as the basis for a future array of imaging atmospheric-Cherenkov telescopes such as AGIS. The scientific goal is a reduction of the energy threshold by a factor…
Stereoscopic viewing of TeV gamma-ray air showers with systems of Imaging Atmospheric Cherenkov Telescopes (IACTs) allows to reconstruct the origin of individual primary particles with an accuracy of 0.1 degree or better. The shower impact…
Observations of air showers with the stereoscopic HEGRA IACT system are usually carried out in a mode where all telescopes point in the same direction. Alternatively, one could take into account the finite distance to the shower maximum and…
Arrays of Cherenkov telescopes typically use multi-level trigger schemes to keep the rate of random triggers from the night sky background low. At a first stage, individual telescopes produce a trigger signal from the pixel information in…
At present, the ground-based astronomy of very high energy (VHE) (E>100 GeV) gamma-rays experiences the challenging transition phase caused by the substantial upgrading of its observational instrumentation. Recently the HEGRA collaboration…
The Cherenkov Telescope Array (CTA) project aims to build the largest ground-based gamma-ray observatory based on an array of Imaging Atmospheric Cherenkov Telescopes (IACTs). The CTA will implement a multi-level trigger system to…
Based on the Monte Carlo simulations we have studied the performance of the HEGRA system of imaging air Cherenkov telescopes (IACTs) in its present configuration of 4 IACTs as well as in its future final configuration of 5 IACTs. Here we…
Imaging atmospheric Cherenkov telescopes (IACTs) are the main technique for detecting gamma rays with energies between tens of GeV and hundreds of TeV. Amongst them, the High Energy Stereoscopic System (H.E.S.S.) has pioneered the use of…
For air showers observed simultaneously by more than two imaging atmospheric Cherenkov telescopes, the shower geometry is overconstrained by the images and image information should be combined taking into account the quality of the images.…
The VERITAS gamma-ray observatory, situated in southern Arizona, is an array of four 12m diameter imaging Cherenkov telescopes, each with a 499-pixel photomultiplier-tube camera. The instrument is designed to detect astrophysical gamma rays…
The next generation of ground-based gamma-ray observatories, such as e.g. CTA, will consist of about 50-100 telescopes, and cameras with in total ~100000 to ~200000 channels. The telescopes of the core array will cover and effective area of…
The Cherenkov Telescope Array (CTA) is a next-generation ground-based observatory for g -rays with energies between some ten GeV and a few hundred TeV. CTA is currently in the advanced design phase and will consist of arrays with different…
In this paper, we present the results of Monte Carlo simulations of atmospheric showers induced by diffuse gamma rays as detected by the high-energy gamma ray astronomy (HEGRA) system of five imaging atmospheric Cerenkov telescopes (IACTs).…
The stereoscopic reconstruction of air showers viewed by multiple imaging atmospheric Cherenkov telescopes (IACTs) allows a more precise reconstruction of shower energies and hence an improved determination of energy spectra. Reconstruction…
The HEGRA system of 4 Imaging Atmospheric Cherenkov Telescopes (IACTs) has been used since March 1997 for a comprehensive study of the gamma-ray emission from the BL Lac object Mkn 501 in the energy range above 500 GeV. Taking advantage of…
The Imaging Atmospheric Cherenkov Telescope (IACT) works by imaging the very short flash of Cherenkov radiation generated by the cascade of relativistic charged particles produced when a TeV gamma ray strikes the atmosphere. This energetic…
The HEGRA system of imaging air Cherenkov telescopes has successfully pioneered the stereoscopic observation technique of extensive air showers. The observational method is briefly described and important results of recent observations of…
H.E.S.S is an array of atmospheric Cherenkov telescopes dedicated to GeV-TeV gamma-ray astronomy. The original array has been in operation since the beginning of 2004. It is composed of four 12-meter diameter telescopes. The installation of…