July 29, 2015 to August 6, 2015
World Forum
Europe/Amsterdam timezone

Observing the Cosmic Ray Moon Shadow with VERITAS

Aug 4, 2015, 4:00 PM
Mississippi Foyer (World Forum)

Mississippi Foyer

World Forum

Churchillplein 10 2517 JW Den Haag The Netherlands
Board: 57
Poster contribution GA-EX Poster 3 GA


Ralph Bird (UCD Dublin)


The Earth is subjected to an isotropic flux of very-high-energy cosmic rays (VHE, E > 100 GeV) unless they are obscured by an object, such as the Moon. The Moon creates a deficit in the uniform flux and, since cosmic rays are charged, this deficit is deflected by the Earth's magnetic field, enabling the rigidity of the obstructed cosmic rays to be determined. Measurement of the relative deficits of different species enables the positron fraction and the antiproton ratio to be measured. The April 15, 2014 lunar eclipse was visible with the VERITAS Cherenkov telescopes, which allowed (with special UV bandpass filters installed) 74 minutes of direct observations of the Moon and the associated deficit in the cosmic-ray flux. The results of this observation will be presented. Additionally VERITAS has been conducting a series of observations by pointing close to a partially illuminated Moon and observing with a reduced high voltage applied to the photo-multiplier-tubes and also using UV bandpass filters. We present the technique developed for these observations and their current status.
Registration number following "ICRC2015-I/" 884
Collaboration VERITAS

Primary author

Ralph Bird (UCD Dublin)

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