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Your search keyword '"Horan, D."' showing total 2 results
2 results on '"Horan, D."'

1. Extragalactic sources of TeV gamma rays: a summary

Author

Horan, D. and Weekes, T.C.

Subjects
*GAMMA rays, *PHOTONS, *ASTRONOMY, *STARBURSTS, *STARS, *RADIO galaxies
Abstract

The development of techniques whereby gamma rays of energy 100 GeV and above can be studied from the ground, using indirect, but sensitive, techniques has opened up a new area of high energy photon astronomy. The most exciting result that has come from these is the detection of highly variable fluxes of TeV gamma rays from the relativistic jets in nearby AGN. The recent detection of signals from a starburst galaxy and from a radio galaxy opens the possibility that the extragalactic emission of TeV gamma rays is a ubiquitous phenomenon. Here we attempt to summarize the properties of the sources detected so far. [Copyright &y& Elsevier]

Published
2004
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2. Focal Plane Detectors for the Advanced Gamma-Ray Imaging System (AGIS).

Author

Otte, A. N., Byrum, K., Drake, G., Falcone, A., Funk, S., Horan, D., Mukherjee, R., Smith, A., Tajima, H., Wagner, R. G., and Williams, D. A.

Subjects
*GAMMA rays, *IMAGING systems, *ASTRONOMY, *PHOTOMULTIPLIERS, *ANODES, *OPTOELECTRONIC devices, *PHOTONS, *TELESCOPES
Abstract

The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. Design goals are ten times better sensitivity, higher angular resolution, and a lower energy threshold than existing Cherenkov telescopes. Simulations show that a substantial improvement in angular resolution may be achieved if the pixel diameter is reduced to the order of 0.05 deg, i.e. two to three times smaller than the pixel diameter of current Cherenkov telescope cameras. At these dimensions, photon detectors with smaller physical dimensions can be attractive alternatives to the classical photomultiplier tube (PMT). Furthermore, the operation of an experiment with the size of AGIS requires photon detectors that are among other things more reliable, more durable, and possibly higher efficiency photon detectors. Alternative photon detectors we are considering for AGIS include both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs). Here we present results from laboratory testing of MAPMTs and SiPMs along with results from the first incorporation of these devices into cameras on test bed Cherenkov telescopes. [ABSTRACT FROM AUTHOR]

Published
2008
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