The Very Energetic Radiation Imaging Telescope Array System or VERITAS is an array of four 12 m diameter imaging atmosphere Cherenkov telescopes. The picture shows the four telescopes at their permanent location at theĀ Fred Lawrence Whipple Observatory (FLWO) observatory one hour south of Tucson, AZ.

VERITAS is sensitive to very-high-energy (VHE) gamma rays in the energy range between ~80 GeV up to several ten TeV. It is one of the most if not the most sensitive instruments in that energy band.

The four VERITAS telescopes take stereoscopic images of air showers that are started by gamma rays and cosmic rays in the upper atmosphere. The images are recorded with four photomultiplier cameras with 499 pixel, each 0.15 degree in diameter by detecting the Cherenkov light that is emitted by the particles in the air shower. The field of view of one camera is 3.5 degrees.

Gamma-rays with such high energies can only be produced by relativistic particles such as cosmic-ray electrons or protons. Thus detecting VHE gamma-rays probes the sites that accelerate cosmic rays to their incredibly high energies. Amongst the about 150 known VHE sources are pulsars, supernova remnants, black holes, and starburst galaxies.

We are experts on studying VHE emission from pulsars with VERITAS. We also use VHE gamma rays from pulsars and other variable sources to test Lorentz invariance. A violation of Lorentz invariance would be a clue to new physics, for example a possible quantum structure of gravity.

Our group members regularly participate in observing shifts. We provide and maintain one of the detector models for Monte-Carlo simulations of VERITAS. Simulations are crucial to understand the data. We also participate in various calibration efforts the lead to a better understanding of the instrument and eventually in better science.