Related papers: Flux Sensitivity of VERITAS
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…
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…
During May 2013, a gamma-ray flare from the BL Lac object 1ES 1727+502 (z=0.055) has been detected with the VERITAS Cherenkov telescopes. This detection represents the first evidence of very-high-energy (E>100 GeV) variability from this…
Significant gamma-ray emission between 1 TeV and 20 TeV from a point source, 1LHAASO J1219+2915, consistent with the location of the LINER/LLAGN galaxy NGC 4278 was recently reported by the LHAASO collaboration. These data were later split…
We report the discovery of very high energy gamma-ray emission from the direction of the SNR G54.1+0.3 using the VERITAS ground-based gamma-ray observatory. The TeV signal has an overall significance of 6.8$\sigma$ and appears point-like…
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 Cherenkov Telescope Array (CTA) is designed to be the next major observatory operating in the Very High Energy (VHE, $\gtrsim 100$ GeV) gamma-ray band. It will build on the imaging atmospheric Cherenkov technique but will go much…
Imaging atmospheric Cherenkov telescopes, such as the Very Energetic Radiation Imaging Tele-scope Array System (VERITAS), are uniquely suited to resolve the detailed morphology ofextended regions of gamma-ray emission. However, standard…
Geminga was first detected as a gamma-ray point source by the SAS-2 gamma-ray satellite observatory and the COS-B X-ray satellite observatory. Subsequent observations have identified Geminga as a heavily obscured radio-quiet pulsar…
The giant radio galaxy M 87 is located at a distance of 16.7 Mpc and harbors a super-massive black hole (6 billion solar masses) in its center. M 87 is one of just three radio galaxies known to emit TeV gamma-rays. The structure of its…
During moonlit nights, observations with ground-based Cherenkov telescopes at very high energies (VHE, $E>100$ GeV) are constrained since the photomultiplier tubes (PMTs) in the telescope camera are extremely sensitive to the background…
The Cherenkov Telescope Array is a next generation ground-based gamma-ray observatory de- signed to detect photons in the 20 GeV to 300 TeV energy range. With a sensitivity improvement of up to one order of magnitude on the entire energy…
The Disp method is an algorithm that is used for reconstruction of primary gamma ray direction in ground- based atmospheric Cherenkov telescope experiments -measuring very-high-energy (VHE) gamma rays in the energy range between 100GeV and…
We present the results of sixteen Swift-triggered GRB follow-up observations taken with the VERITAS telescope array from January, 2007 to June, 2009. The median energy threshold and response time of these observations was 260 GeV and 320 s,…
The Large Zenith Telescope Survey whose construction is almost completed (first light expected in spring 2002) near Vancouver (Canada) is designed to observed a total strip of ~17' x 120 deg in 40 medium-band filters spanning 4000-10000 A.…
In 2018-2019 the VERITAS VHE gamma-ray observatory was augmented with highspeed optical instrumentation and continuous data recording electronics to create a sensitive Stellar Intensity Interferometry (SII) observatory, VERITAS-SII. The…
Current detectors for Very-High-Energy $\gamma$-ray astrophysics are either pointing instruments with a small field of view (Cherenkov telescopes), or large field-of-view instruments with relatively large energy thresholds (extensive air…
The Cherenkov Telescope Array (CTA) is a ground-based $\gamma$-ray observatory that will observe the full sky in the energy range from 20 GeV to 100 TeV from facilities in both hemispheres. It is proposed to consist of more than 100…
The recent detection by the Fermi gamma-ray space telescope of high-energy gamma-rays from the radio galaxy NGC 1275 makes the observation of the very high energy (VHE: E > 100 GeV) part of its broadband spectrum particularly interesting,…
The VERITAS Cherenkov telescope array has been fully operational since Fall 2007 and has fulfilled or outperformed its design specifications. We are preparing an upgrade program with the goal to lower the energy threshold and improve the…