The Fluorescence Detector of the Pierre Auger Observatory
Abstract
The Pierre Auger Observatory is a facility designed for the study of ultra-high energy cosmic rays. The Observatory combines two different types of detectors: a surface array of 1600 water Cherenkov stations placed on a 1.5 km triangular grid covering over 3000 km2; and a fluorescence detector of 24 telescopes located in 4 buildings at the perimeter of the surface array. The fluorescence telescopes, each consisting of 440 photomultipliers, collect the ultraviolet light produced when the charged secondary particles in an air shower excite nitrogen molecules in the atmosphere. Because the intensity of the nitrogen fluorescence is proportional to the energy deposited in the atmosphere during the air shower, the air fluorescence measurements can be used to make a calorimetric measurement of the cosmic ray primary energy. Showers observed independently by the surface array and fluorescence telescopes, called hybrid events, are critical to the function of the Observatory, as they allow for a model-independent calibration of the surface detector. In this paper I describe the detector and the most important measurements.
- Publication:
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Journal of Physics Conference Series
- Pub Date:
- April 2011
- DOI:
- 10.1088/1742-6596/293/1/012036
- arXiv:
- arXiv:1011.6523
- Bibcode:
- 2011JPhCS.293a2036N
- Keywords:
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- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- Proceedings of XIV International Conference on Calorimetry in High Energy Physics (Calor 2010), Beijing, China, 2010 submitted to IOP proceedings to be published in Journal of Physics: Conference Series