Related papers: The throughput calibration of the VERITAS telescop…
Context. The response of imaging atmospheric Cherenkov telescopes to incident {\gamma}-ray-initiated showers in the atmosphere changes as the telescopes age due to exposure to light and weather. These aging processes affect the…
The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic Radiation Imaging Telescope Array System) has been in operation since February 2005. We present here a technical description of the instrument and a summary of its…
As a calibrated laser pulse propagates through the atmosphere, the intensity of the Rayleigh scattered light arriving at the VERITAS telescopes can be calculated precisely. This allows for absolute calibration of imaging atmospheric…
VERITAS is an array of four identical telescopes designed for detecting and measuring astrophysical gamma rays with energies in excess of 100 GeV. Each telescope uses a 12 m diameter reflector to collect Cherenkov light from air showers…
A calibrated laser pulse propagating through the atmosphere produces a flash of Rayleigh scattered light with an intensity that can be calculated very accurately when atmospheric conditions are good. This is used in a technique developed…
For reliable event reconstruction of Imaging Atmospheric Cherenkov Telescopes (IACTs), calibration of the optical throughput efficiency is required. Within current facilities, this is achieved through the use of ring shaped images generated…
VERITAS is a system of four imaging Cherenkov telescopes located at the Fred Lawrence Whipple Observatory in southern Arizona. We present here results of detailed Monte Carlo simulations of the array response to extensive air showers.…
Atmospheric monitoring is an integral part of the design of the Cherenkov Telescope Array (CTA), as atmospheric conditions affect the observations by Imaging Atmospheric Cherenkov Telescopes (IACT) in multiple ways. The variable optical…
The presence of moonlight is usually a limiting factor for imaging atmospheric Cherenkov telescopes due to the high sensitivity of the camera photomultiplier tubes (PMTs). In their standard configuration, the extra noise limits the…
The atmosphere is an intrinsic part of any ground based Cherenkov gamma-ray telescope, and the telescope response is therefore sensitive to unpredictable changes in the atmospheric transparency which are difficult to measure and interpret…
As a calibrated laser pulse propagates through the atmosphere, the amount of Rayleigh-scattered light arriving at the VERITAS telescopes can be calculated precisely. This technique was originally developed for the absolute calibration of…
Gamma-ray astronomy at energies in excess of 100 GeV is carried out using arrays of imaging Cherenkov telescopes. Each telescope comprises a large reflector, of order 10 m diameter, made of many mirror facets, and a camera consisting of a…
Context. The presence of clouds during observations with Imaging Atmospheric Cherenkov Telescopes can strongly affect the performance of the instrument due to additional absorption of light and scattering of light beyond the field of view…
The Cherenkov Telescope Array (CTA) is the next-generation stereoscopic system of Imaging Atmospheric Cherenkov Telescopes (IACTs). In IACTs, the atmosphere is used as a calorimeter to measure the energy of extensive air showers induced by…
The Cherenkov Telescope Array (CTA) will be the next generation observatory employing different types of Cherenkov telescopes for the detection of particle showers initiated by very-high-energy gamma rays. A good knowledge of the Earth's…
Calibration of a PMT matrix is crucial for the treatment of the data obtained with Cherenkov tracking detector. Furthermore, due to high variability of the aerosol abundance in the atmosphere depending on season, weather etc. A constant…
In this article we discuss the possibility of using the observations by GLAST of standard gamma sources, as the Crab Nebula, to calibrate Imaging Air Cherenkov detectors, MAGIC in particular, and optimise their energy resolution. We show…
The reflector used by an imaging atmospheric Cherenkov telescope (IACT) consists of a tessellated array of mirrors mounted on a large frame. This arrangement allows for a very large reflecting surface with sufficient optical quality for the…
The atmospheric monitoring devices for the planned calibration system of the Cherenkov Telescope Array (CTA) are undergoing intensive development, prototyping and testing. The All-Sky Cameras, the Sun/Moon Photometers and the FRAM…
Current Imaging Atmospheric Cherenkov Telescopes for Very High Energy $\gamma$-ray astrophysics are pointing instruments with a Field of View up to a few tens of sq deg. We propose to build an array of two non-steerable (drift) telescopes.…