Transcript Slide 1
www.auger.org Introduction to the Pierre Auger Observatory Paul Sommers, August 26, 2008 Auger The Cosmic Ray Energy Spectrum Non-thermal, approximate power law, up to about 3x1020 eV (possibly higher) 1 EeV = 1018 eV 6 EeV ≈ 1 Joule [Simon Swordy] Cosmic ray energy spectrum Knee multiplied by E2.5 Ankle Toes? Charged particle astronomy is plausible above the GZK energy threshold because the isotropic background from distant sources is eliminated. [Cronin] To a proton above about 60 EeV, the CMB photons appear to be a beam of gamma rays energetic enough to produce a pion by collision. Protons cannot travel more than ~100 Mpc without falling below that energy threshold. Also, magnetic deflection is much reduced for protons near and above the GZK energy threshold. Earth Galaxy center Objectives Identify sources of cosmic rays. At the highest energies, cosmic ray arrival directions should correspond to the source positions on the sky: Very high magnetic rigidity (little path bending, if protons) Sources must be “nearby” because of the GZK effect Learn about how the highest energy particles are produced by studying the properties of the sources which produce them. Study properties of nuclear collisions at energies much higher than can be obtained at collider laboratories like LHC. The Auger Observatory Hybrid Design Surface array of 1600 water Cherenkov tanks covering 3000 km2. Air fluorescence detectors observe the atmosphere above the array. Exploring the Auger Observatory With Google Earth Viewing the Auger Observatory with Google Earth Download GoogleEarth from http://earth.google.com/download-earth.html Visit http://www.auger.org/observatory/ Follow the link to “Explore the Auger Observatory with Google Earth” That takes you to a site with instructions for downloading the 3D buildings, event displays, etc., which have been developed by Stephane Coutu. The Auger Collaboration Founders: Jim Cronin Alan Watson Participating Countries Argentina Australia Bolivia Brazil Czech Republic France Germany Italy Mexico Netherlands Poland Portugal Slovenia Spain United Kingdom United States Vietnam Layout of Auger South PRESENT STATUS OF THE ARRAY Ingo Allekotte, SD Status Report – Malargue November 2004 Auger Water Cherenkov Detector Solar panel and electronic box GPS antenna Comm antenna Three 8” PM Tubes White light diffusing liner De-ionized water Battery box Plastic tank 30o x 30o Field of View 2.2m diameter aperture stop with Schmidt corrector ring. UV-Filter 300-400 nm 3.8m x 3.8m mirror camera 440 PMTs corrector lens To see LOTS of Auger event displays Go to www.auger.org and select the link: Event Display Deployment is complete! Tank #1600 was filled in May 2008 New Developments Underway •High Elevation Auger Telescopes (HEAT) •Auger Muons and Infill for the Ground Array (AMIGA) •Radio detection and measurement of air showers (R&D) •Auger North Recently completed enclosures for 3 telescopes at Coihueco that will view elevation angles between 30 and 60 degrees in order to look up at nearby showers (the only way to measure lower energy showers). HEAT Auger North Because 30 events/year is not enough! We need thousands for cosmic ray astronomy (individual source spectra) Because we want to see nearby sources also in the northern sky. Because we should map the full sky above and below the GZK threshold. (20,000 km2) The particle physics is most interesting at the highest energies where the flux is minuscule. 7 times the collecting area of Auger South. Area equal to Massachusetts. Full coverage by fluorescence detectors. Thank You