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HEP: The transient universe at TeV energies

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Manel Errando, Columbia University
05 November 2014 from 2:30 PM to 3:30 PM
339 Davey Laboratory
Contact Name
Miguel Mostafa
Contact Phone
(814) 865-4306
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The VERITAS array of atmospheric Cherenkov telescopes in southern Arizona is one of the world’s most sensitive detectors of TeV gamma rays. Photons at these energies trace the most extreme cosmic particle accelerators, linking together the highest-energy astrophysical messengers: gamma rays, cosmic rays, and neutrinos.

The TeV sky is remarkably variable. Flux variability has been reported in TeV-detected binary systems and in the vast majority of active galactic nuclei, with flaring states that often exceed the quiescent flux by more than on order of magnitude. The VERITAS efforts to detect and respond to multiwavelength alerts for transient events will be discussed. Recent results from such campaigns include the detection of sub-hour TeV flux variability from BL Lacertae, and first results from an observing campaign on the quasar 3C 279 in April 2014 during the brightest gamma-ray outburst ever recorded for this object, with flux exceeding the historic 1991 flare seen by EGRET. These observations present strong challenges to current models of energy dissipation in relativistic jets, especially concerning the role of ambient photon fields in the radiation mechanisms, and the size and location of the gamma-ray emission region.