This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). It will provide funds to work on the Pierre Auger Observatory in Malargue, Argentina. The Observatory is the world's largest detector for "ultra-high energy" cosmic rays. The data promises to shed light on the origin of these cosmic rays, the highest energy particles of the (known) Universe. The measured energy spectrum of cosmic rays extends up to eleven orders of magnitude greater than the equivalent rest mass of the proton. No single source or source class is expected to be responsible for the flux over such a wide range of energies. The large energies of these particles imply that they are accelerated in violent processes in extreme astrophysical objects, for example Active Galactic Nuclei, which contain supermassive black holes, or Gamma Ray Bursts. With its major involvement in IceCube and in neutrino physics and phenomenology, UW-Madison is a natural place to explore the possibilities of the Pierre Auger Observatory as a neutrino detector, and to further study the connection between cosmic rays and neutrinos.

The PI's areas of particular strength and interest are the search for discrete sources and anisotropies in the cosmic ray arrival direction distribution and the search for neutrinos at ultra-high energies. His second main effort will be the study of the atmosphere and its influence on cosmic ray measurements. The energy calibration of the detector relies on the air fluorescence detector and requires corrections for atmospheric absorption and scattering to be applied.

The broader impact of the program includes outreach activities aimed at enhancing the public's understanding of science, for example through brochures like "Cosmic Extremes" and involving K-12 teachers and high school students in ongoing research.

Agency
National Science Foundation (NSF)
Institute
Division of Physics (PHY)
Type
Standard Grant (Standard)
Application #
0855300
Program Officer
James J. Whitmore
Project Start
Project End
Budget Start
2009-08-01
Budget End
2011-12-31
Support Year
Fiscal Year
2008
Total Cost
$284,000
Indirect Cost
Name
University of Wisconsin Madison
Department
Type
DUNS #
City
Madison
State
WI
Country
United States
Zip Code
53715