Related papers: Large zenith angle observations with the high-reso…
Radio-detection is becoming an established technique for the detection of air showers induced by cosmic particles. This is in particular true at the highest energies, where very large detection areas are required. A proper description of…
In 2012, the High Energy Stereoscopic System (H.E.S.S.) was expanded by a fifth telescope (CT5). With an effective mirror diameter of 28m, CT5 is able to detect the Cherenkov light of very faint gamma-ray air showers, thereby significantly…
We report on the status of the Tierras Observatory, a refurbished 1.3-m ultra-precise fully-automated photometer located at the F. L. Whipple Observatory atop Mt. Hopkins, Arizona. Tierras is designed to limit systematic errors, notably…
The Telescope Array Low-Energy Extension (TALE) is a hybrid, Air Fluorescence Detector (FD) / Scintillator Array, designed to study cosmic ray initiated showers at energies above $\sim3\times10^{16}$ eV. Located in the western Utah desert,…
Imaging Atmospheric Cherenkov Telescopes (IACTs) are very-large telescopes designed to detect the nanosecond-timescale flashes produced within extended air showers. Because IACTs are sensitive to the Cherenkov light (UV/blue) and use…
The Cherenkov Telescope Array (CTA) is planned to be the next-generation very-high-energy (VHE; E > 100 GeV) gamma-ray observatory. It is anticipated that CTA will improve upon the sensitivity of the current generation of VHE experiments,…
We present a method of atmospheric Cherenkov imaging which reconstructs the unique arrival direction of TeV gamma rays using a single telescope. The method is derived empirically and utilizes several features of gamma-ray induced air…
We present 220 GHz (1.36 mm) measurements of zenith optical depth obtained to characterise the Indian Astronomical Observatory, Hanle (Ladakh, India) during the period from late December 1999 to early May 2000 and early October 2000 to…
Very high energy gamma-ray astronomy based on the measurement of air shower particles at ground-level has only recently been established as a viable approach, complementing the well established air Cherenkov technique. This approach…
In this paper we propose a 'knee-like' approximation of the lateral distribution of the Cherenkov light from extensive air showers in the energy range 30-3000 TeV and study a possibility of its practical application in high energy…
The Cherenkov Telescope Array (CTA) will be the world's largest and by far most sensitive observatory for high-energy gamma rays. It will be capable of detecting gamma rays from extremely faint sources with unprecedented precision on energy…
We present the first strong detection of very high energy gamma-rays from the close (z=0.048) X-ray selected BL Lacertae object 1ES1959+650. Observations were made with the Whipple 10m telescope on Mt. Hopkins, Arizona, using the…
Future experiments based on the observation of Earth's atmosphere from sub-orbital and orbital altitudes plan to include optical Cherenkov cameras to observe extensive air showers produced by high-energy cosmic radiation via its interaction…
The High-Altitude Water Cherenkov (HAWC) observatory is a second-generation continuously operated, wide field-of-view, TeV gamma-ray observatory. The HAWC observatory and its analysis techniques build on experience of the Milagro experiment…
Nighttime zenith sky spectral brightness in the 3.3 to 20 micron wavelength region is reported for an observatory site nearby Eureka, on Ellesmere Island in the Canadian High Arctic. Measurements derive from an automated Fourier-transform…
The Cherenkov Telescope Array (CTA) is the next generation ground-based observatory for gamma-ray astronomy at very-high energies. It will be capable of detecting gamma rays in the energy range from 20 GeV to more than 300 TeV with…
The photon detection efficiency of two sets of R10560-100-20 superbialkali photomultiplier tubes from Hamamatsu were measured between 200 nm and 750 nm to quantify a possible degradation of the photocathode sensitivity after four years of…
The ground-based gamma-ray observatory VERITAS (Very Energetic Radiation Imaging Telescope Array System) is sensitive to photons of astrophysical origin with energies in the range between $\approx 85$ GeV to $\approx 30$ TeV. The instrument…
The observation of very-high-energy (VHE, E>100 GeV) gamma rays is mediated by the imaging atmospheric Cherenkov technique (IACTs). At these energies, gamma rays interact with the atmosphere to create a cascade of electromagnetic air…
The 2.5m Isaac Newton Telescope(INT) is currently being used to carry out a major multi-colour, multi-epoch, CCD based wide field survey over an area of 100 square degrees. The survey parameters have been chosen to maximise scientific…