English
Related papers

Related papers: Recent Results from VERITAS AGN Observations

200 papers

VERITAS, the Very Energetic Radiation Telescope Imaging Array System, is an array of four imaging Atmospheric Cherenkov telescopes in southern Arizona. It is sensitive to gamma rays at energies above 100 GeV. Here, we discuss the results of…

Astrophysics · Physics 2007-09-25 S. J. Fegan

Large number of Active Galactic Nuclei (AGN) producing Very-High-Energy (VHE) gamma-rays (energies above 100~GeV) has been revealed using observations with Imaging Atmospheric Cherenkov Telescopes (IACTs). However, our knowledge of the VHE…

High Energy Astrophysical Phenomena · Physics 2025-06-11 A. Neronov , D. Semikoz

Gamma-ray binaries are variable sources of GeV-to-TeV photons with the peak in their spectral energy distributions above 100 MeV. There are only five Galactic gamma-ray binaries known and the processes which govern particle acceleration,…

High Energy Astrophysical Phenomena · Physics 2017-08-15 Gernot Maier , the VERITAS Collaboration

The Cygnus region of the galaxy is one of the richest regions of gas and star formation and is the brightest region of diffuse GeV emission in the northern sky. VERITAS has conducted deep observations (approximately 300 hours) in the…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Ralph Bird

Very high energy (VHE; >100 GeV) observations of a sample of selected active galactic nuclei (AGN) were performed between January 2005 and April 2007 with the High Energy Stereoscopic System (HESS), an array of imaging atmospheric-Cherenkov…

Astrophysics · Physics 2007-10-01 HESS Collaboration , W. Benbow , R. Buehler

VERITAS (the Very Energetic Radiation Imaging Telescope Array System) is the next generation ground-based gamma-ray observatory that is being built in southern Arizona by a collaboration of ten institutions in Canada, Ireland, the U.K. and…

Astrophysics · Physics 2019-08-14 Peter Cogan

The BL Lac object 1ES 0229+200 is a firmly established very-high-energy (VHE; E >100 GeV) source. Located at a redshift of 0.1396, its published VHE spectrum is particularly hard (Gamma ~2.5) and is widely used to perform studies on the…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Matteo Cerruti

We report on the VERITAS detection of very-high-energy (VHE, $E > 100~\mathrm{GeV}$) $\gamma$-ray emission from the optically bright quasar OJ 287 which is located at a redshift of z = 0.306. OJ 287 has been observed to display regular…

High Energy Astrophysical Phenomena · Physics 2017-08-08 Stephan O'Brien

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…

Astrophysics · Physics 2019-08-13 David Hanna

A few Galactic objects are known to be variable sources of photons with energies above 100 GeV. These systems are mostly binaries, where variability can often be connected to the orbital period. Particle acceleration and gamma-ray…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Gernot Maier

X-ray binaries stand as the brightest X-ray sources in the galaxy, showing both variable X-ray emission and extreme flares. Some of these systems have been recently discovered to be TeV gamma-ray emitters, with the high energy emission…

High Energy Astrophysical Phenomena · Physics 2019-08-13 R. Guenette

The study of $\gamma$-ray emission from galactic sources such as supernova remnants (SNR) may provide key insights into their potential role as accelerators of cosmic rays up to the knee ($\sim 10^{15}$ eV). The VERITAS Observatory is…

High Energy Astrophysical Phenomena · Physics 2019-08-14 A. Weinstein

Clusters of galaxies are one of the few prominent classes of objects predicted to emit gamma rays not yet detected by satellites like EGRET or ground-based Imaging Atmospheric Cherenkov Telescopes (IACTs). The detection of Very High Energy…

Astrophysics · Physics 2019-08-13 J. S. Perkins

The improved sensitivity of current-generation atmospheric-Cherenkov telescope (ACT) arrays enables us to probe for the first time low-frequency-peaked and intermediate-frequency-peaked BL Lac (LBL and IBL, respectively) objects as very…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Pratik Majumdar

This White Paper explores advances in the study of Active Galaxies which will be enabled by new observing capabilities at MeV energies (hard X-rays to gamma-rays; 0.1-1000 MeV), with a focus on multi-wavelength synergies. This spectral…

We report the detection of very high energy gamma-ray emission from the blazar S3 1227+25 (VER J1230+253) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). VERITAS observations of the source were triggered by the…

The giant radio galaxy M87 is the only extragalactic non-blazar object which has been detected as a source of very high energy gamma-rays. It represents a unique opportunity to study the phenomena of gamma-ray emission from a nearby AGN. In…

Astrophysics · Physics 2007-09-25 Pierre Colin

The HAWC observatory recently published their second source catalog with 39 very high energy gamma-ray sources based on 507 days of exposure time. Among these, there were 16 sources that are more than one degree away from any known TeV…

High Energy Astrophysical Phenomena · Physics 2019-08-15 Nahee Park