Observatory

SD Tank of the Pierre Auger Observatory in Malargüe, Mendoza Province near the Andes range

Back view of a tank

Pierre Auger Observatory is an international cosmic ray observatory designed to detect ultra high energy cosmic rays -- Oh-My-God particles. These are sub-atomic particles (protons or other nuclei) with energies beyond 10²⁰ electron-volts, the energy of a tennis ball traveling at 53.3 miles per hour, but packed into a single subatomic particle. These high energy particles have an estimated arrival rate of just 1 per square kilometer per century, therefore, in order to record a large number of these events, the Auger Observatory has created a detection area the size of Rhode Island in western Argentina's Mendoza Province. Image File history File links Metadata Size of this preview: 800 × 599 pixelsFull resolution (2848 × 2134 pixel, file size: 1. ... Image File history File links Metadata Size of this preview: 800 × 599 pixelsFull resolution (2848 × 2134 pixel, file size: 1. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Planes view of the Andes, Peru. ... Image File history File links Metadata Size of this preview: 800 × 599 pixelsFull resolution (2848 × 2134 pixel, file size: 1. ... Image File history File links Metadata Size of this preview: 800 × 599 pixelsFull resolution (2848 × 2134 pixel, file size: 1. ... Cosmic rays can loosely be defined as energetic particles originating outside of the Earth. ... Unsolved problems in physics: Why is it that some cosmic rays appear to possess energies that are theoretically too high? In high-energy physics, an ultra-high-energy cosmic ray (UHECR) is a cosmic ray (subatomic particle) which appears to have extreme kinetic energy, far beyond both its rest mass... An electronvolt (symbol: eV) is the amount of energy gained by a single unbound electron when it falls through an electrostatic potential difference of one volt. ... Mendoza is one of the 23 provinces of Argentina, located in the western central part of the country in the Cuyo region. ...

The observatory was named after the French physicist Pierre Victor Auger. The observatory project was proposed in 1992 by Jim Cronin and Alan Watson. Today, more than 200 physicists from 55 institutions around the world are collaborating to build the southern site. The 15 participating countries are sharing the $50 million construction budget, each providing a minor part of the total cost. Pierre Victor Auger (May 14, 1899 - December 25, 1993) was a French physicist, born in Paris. ... James Watson Cronin (born September 29, 1931) is an American nuclear physicist. ...

The observatory will consist of northern and southern sites. The southern site is in the final phase of construction and is currently operating and collecting data. It became the largest ultra-high energy cosmic ray detector in the world in 2003. It is located on the vast plane of Pampa Amarilla, near the town of Malargüe in Mendoza Province, Argentina. The northern site will be located in southeastern Colorado, United States and hosted by Lamar Community College. Malargüe is a town of approximately 20,000 inhabitants which is the capital of the department of Malargüe in the southwest part of the province of Mendoza in Argentina. ... Mendoza is one of the 23 provinces of Argentina, located in the western central part of the country in the Cuyo region. ... Official language(s) English Capital Denver Largest city Denver Area  Ranked 8th  - Total 104,185 sq mi (269,837 km²)  - Width 280 miles (451 km)  - Length 380 miles (612 km)  - % water 0. ...

Each site of the final observatory will consist of 1600 water tanks (Water Cherenkov Detectors) distributed over 3000 km² (similar to the Haverah Park experiment) overseen by four atmospheric fluorescence detectors similar to the High Resolution Fly's Eye. Cherenkov effect at the UMRs nuclear reactor Cherenkov radiation (also spelled Cerenkov) is electromagnetic radiation emitted when a charged particle passes through an insulator at a speed greater than that of light in the medium. ... The Haverah Park experiment was a cosmic ray air shower detection array consisting of water Cherenkov detectors distributed over an area of 12km² on Haverah Park in North Yorkshire Moors, UK. The experiment was operated by University of Leeds for 20 years until 1987 when it was switched off. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... The HiRes detector - an atmospheric fluorescence detector: HiRes currently consists of two sites on top of two mountains separated by 13km in western Utah. ...

The PAO is unique in that it is the first experiment that combines both ground and fluorescence detectors at the same site thus allowing cross-calibration and reduction of systematic effects that may be peculiar to each technique.

The Cherenkov detectors use 3 large photomultiplier tubes to detect the light produced by high-energy particles passing through water in the tank. The time of arrival of high-energy particles from the same shower at several tanks is used to calculate the direction of travel of the original particle. Cherenkov radiation glowing in the core of a TRIGA reactor Cherenkov radiation (also spelled Cerenkov or sometimes ÄŒerenkov) is electromagnetic radiation emitted when a charged particle passes through an insulator at a speed greater than the speed of light in that medium. ...

The fluorescence detectors are used to track the particle shower's glow on dark nights, as it descends through the atmosphere.

External links

• Pierre Auger Observatory
• Southern site website (Spanish and English)
• Let It Rain Symmetry February 2005
• COSMUS visuals for the PAO : includes movies, animated 3d models of cosmic ray showers over the Malargues site, and stereo photographs.

Coordinates: 35°28′00″S, 69°18′41″W Map of Earth showing lines of latitude (horizontally) and longitude (vertically), Eckert VI projection; large version (pdf, 1. ...