Related papers: Astrophysical measurements with the VERITAS Stella…
Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances, and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light,…
The study of Young Stellar Objects (YSOs) is one of the most exciting topics that can be undertaken by long baseline optical interferometry. The magnitudes of these objects are at the edge of capabilities of current optical interferometers,…
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 current generation of Imaging Atmospheric Cherenkov telescopes are allowing the sky to be probed with greater sensitivity than ever before in the energy range around and above 100 GeV. To minimise the systematic errors on derived fluxes…
More than sixty years after the first intensity correlation experiments by Hanbury Brown and Twiss, there is renewed interest for intensity interferometry techniques for high angular resolution studies of celestial sources. We report on a…
The Imaging Atmospheric Cherenkov Technique (IACT) is unusual in astronomy as the atmosphere actually forms an intrinsic part of the detector system, with telescopes indirectly detecting very high energy particles by the generation and…
Gamma ray observations from a few hundred MeV up to tens of TeV are a valuable tool for studying particle acceleration and diffusion within our galaxy. Constructing a coherent physical picture of particle accelerators such as supernova…
The angular size of a star is a critical factor in determining its basic properties. Direct measurement of stellar angular diameters is difficult: at interstellar distances stars are generally too small to resolve by any individual imaging…
Intensity interferometry removes the stringent requirements on mechanical precision and atmospheric corrections that plague all amplitude interferometry techniques at the cost of severely limited sensitivity. A new idea we recently…
Ground-based composition measurements of high-energy cosmic rays can be significantly improved by using the direct Cherenkov method. This technique targets the Cherenkov light produced by the primary particle prior to its production of an…
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…
This white paper briefly summarizes stellar science opportunities enabled by ultra-high resolution (sub-100 {\mu} arc-sec) astronomical imaging in the visible (U/V) wavebands. Next generation arrays of Imaging Cherenkov telescopes, to be…
Recent advances in telescope design, photodetector efficiency, and high-speed electronic data recording and synchronization have created the observational capability to achieve unprecedented angular resolution for several thousand bright…
The construction of the Cherenkov Telescope Array is expected to start soon. We will present the baseline methods and their extensions currently foreseen to calibrate the observatory. These are bound to achieve the strong requirements on…
The sensitivity of imaging atmospheric Cherenkov telescopes (IACTs) in TeV gamma-ray observations reachs its maximum at small zenith angles (< 30 degree) which provide the minimum attainable energy threshold of an instrument. However, for a…
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…
The site selection group for the future Cherenkov Telescope Array (CTA) has deployed sensitive light sensors at 9 candidate sites, 5 of them in the Southern and 4 in the Northern hemisphere. The sensors are equipped with a PIN diode and a…
We present a new measurement of the energy spectrum of iron nuclei in cosmic rays from 20 to 500 TeV. The measurement makes use of a template-based analysis method, which, for the first time, is applied to the energy reconstruction of…
The VERITAS array of 12-m atmospheric-Cherenkov telescopes is used in an intensive observation program focused on the discovery of VHE (E > 100 GeV) gamma-ray-emitting blazars. Since VERITAS began full-scale operation in 2007, more than…
The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to the VHE gamma-ray astrophysics in the energy range 30 GeV-100 TeV, which will improve by about one order of…