Thursday, February 20th, 1:00 p.m.
Dolan E133

Corbin E. Covault, Professor of Physics at Case Western Reserve University will give a talk on, “The Persistent Mystery of the Highest Energy Cosmic Rays”.

Abstract
Cosmic rays are high-energy particles arriving to the Earth from all directions in space. The origin and nature of cosmic rays, especially at the highest energies, has remained a profound mystery, attracting the attention of both astrophysicist and particle physicists. The Pierre Auger Observatory is the world’s largest experiment to measure the properties of cosmic rays at the highest energies, up to 10^{20} eV or more. Auger is a hybrid detector consisting of two coincident but distinct detector systems: (1) an array of 1,660 water-Cherenkov Surface Detector stations spread over 3,000 square kilometers area for detecting air shower particles on the ground; and (2) a set of four Fluorescence Detector telescopes which provide calorimetric measurements of the development of cosmic ray showers as they propagate through the atmosphere. Located near Malargue in Argentina, Auger has been collecting data continuously since 2004. We’ll describe some of our recent results from Auger for the measurement of the all-particle cosmic ray energy spectrum, arrival directions, and atomic composition . We also describe recent searches for point sources and large-angle anisotropies. All of these new results place significant constraints on theory and may be leading to a final deeper understanding of where in the universe cosmic rays are created, how they are accelerated, and how the propagate to us.