A search for ultra-high-energy gamma rays from active galactic nuclei.

Extensive air shower data collected using the CASA-MIA detector are examined for evidence of gamma ray emission at median energies above 50 TeV from the directions of twenty-six active galactic nuclei. These objects have all been detected previously at energies above 100 MeV by the Energetic Gamma Ray Experiment Telescope aboard the Compton Gamma Ray Observatory. No evidence of continuous or short term gamma ray emission is found for data collected between March, 1990 and December, 1993. The flux limits calculated from this data are consistent with microwave attenuation of the gamma ray signal.PhDPhysicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/104267/1/9513314.pdfDescription of 9513314.pdf : Restricted to UM users only