Paul Sommers, UHE CR experiments and prospects & GRB

Mar 18, 1999 UHE CR experiments and prospects & GRB Paul Sommers Cosmic rays near 10^20 eV and above are rapidly attenuated by the microwave background radiation. Such particles should travel to us from less than 50 Mpc without significant magnetic deflection. It is puzzling that the highest energy particle arrival directions do not point to astrophysical radio sources. Are they produced by transient phenomena like GRBs? The spectrum due to any cosmologically distributed sources should show a strong suppression at the GZK threshold. The recent spectrum from AGASA would seem to be inconsistent with sources distributed throughout the universe, but lack of obvious anisotropy argues against dominance by a local source. The Fly's Eye spectrum is more compatible with a GRB 1/E^2 spectrum above the ankle. New and more powerful detectors should clarify the situation. The HiRes detector will begin full operation this year in Utah. The international Auger Project had a groundbreaking ceremony yesterday in Argentina. I will describe plans for the Auger Observatory.

Audio for this talk requires sound hardware, and RealPlayer or RealAudio by RealNetworks.

Begin continuous audio for the whole talk. (Or, right-click to download the whole audio file.)

To begin viewing slides, click on the first slide below.