Related papers: VERITAS Observations of Extragalactic Non-Blazars
Most of the ~50 blazars detected to date at TeV energies (E>0.1 TeV) are high-frequency-peaked BL Lacs (HBLs). Only a handful episodic TeV detections of low- and intermediate-frequency-peaked BL Lacs (LBL/IBLs, with synchrotron peak…
The galaxy M82 has long been considered a promising target for VHE gamma-ray observations because of the compact starburst region in its core. Theoretical predictions have suggested it should be detectable by ground-based imaging Cherenkov…
We report on the discovery of two gamma-ray sources at E > 200 GeV with VERITAS: RX J0648.7+1516 and VER J0521+211. Both sources are located at low galactic latitudes (|b| < 10 deg), and were previously classified as active galactic nuclei…
The launch of the Fermi gamma-ray space telescope and the imaging air Cerenkov telescopes H.E.S.S., MAGIC, and VERITAS have substantially transformed our knowledge of gamma-ray sources in the last decade. The extragalactic gamma-ray sky is…
The Galactic Center has long been a region of interest for high-energy and very-high-energy observations. Many potential sources of GeV/TeV gamma-ray emission have been suggested, e.g., the accretion of matter onto the black hole, cosmic…
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…
The development of the atmospheric Cherenkov imaging technique has led to significant advances in gamma-ray detection sensitivity in the energy range from 200 GeV to 50 TeV. The Whipple Observatory 10m reflector has detected the first…
The results of the first extragalactic gamma-ray survey by the High Energy Stereoscopic System (H.E.S.S.) are presented. The survey comprises 2720 hours of very high-energy gamma-ray observations of the extragalactic sky, recorded with…
We present very-high-energy $\gamma$-ray observations of the BL Lac object 1ES 2344+514 taken by the Very Energetic Radiation Imaging Telescope Array System (VERITAS) between 2007 and 2015. 1ES 2344+514 is detected with a statistical…
We report on VERITAS observations of the BL Lac object B2 1215+30 between 2008 and 2012. During this period, the source was detected at very high energies (VHE; E > 100 GeV) by VERITAS with a significance of $8.9\sigma$ and showed clear…
Here we present highlights from VERITAS observations of high-frequency-peaked BL Lac objects (HBLs). We discuss the key science motivations for observing these sources -- including performing multiwavelength campaigns critical to…
The High Energy Stereoscopic System (H.E.S.S.) experiment, a ground-based gamma-ray Cherenkov telescope array located in Namibia, has now detected many extragalactic objects, which redshifts range from z=0.00183 up to z=0.2, possibly more.…
The high-mass X-ray binary system LS I +61 303 is well known as a rare example of a variable Galactic GeV and TeV gamma-ray emitter. Despite years of study, many aspects of the system remain unclear; the nature of the compact object, the…
VERITAS is one of the world's most sensitive detectors of astrophysical VHE (E $>$ 100 GeV) gamma rays. This array of four 12-m imaging atmospheric-Cherenkov telescopes has operated for 12 years, and $>$6,000 hours of observations have been…
The galactic center (GC) has long been a region of interest for high-energy and very-high-energy observations. Many potential sources of GeV/TeV gamma-ray emission are located in the GC region, e.g. the accretion of matter onto the central…
Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E>100 GeV) {\gamma}-ray sources. In…
Blazars are jetted active galactic nuclei with a jet pointing close to the line of sight, hence enhancing their intrinsic luminosity and variability. Monitoring these sources is essential in order to catch them flaring and promptly organize…
VERITAS is a ground-based gamma-ray observatory that uses the imaging atmospheric Cherenkov technique and operates in the very high-energy (VHE) region of the gamma- ray spectrum from 100 GeV to 50 TeV. The observatory consists of an array…
Assuming Galactic cosmic rays originate in supernovae and the winds of massive stars, starburst galaxies should produce very-high-energy (VHE; E$>$100 GeV) gamma-ray emission via the interaction of their copious quantities of cosmic rays…
The study of supernova remnants and pulsar wind nebulae was one of the Key Science Projects for the first two years of VERITAS observations. VERITAS is an array of four imaging Cherenkov telescopes located at the Whipple Observatory in…