Thursday, November 08, 2007

Highest-energy Cosmic Rays Linked With Violent Black Holes

The first major result coming out of Pierre Auger observatory has now been reported.

Using the Pierre Auger Observatory in Argentina, the largest cosmic-ray observatory in the world, a team of scientists from 17 countries found that the sources of the highest-energy particles are not distributed uniformly across the sky. Instead, the Auger results link the origins of these mysterious particles to the locations of nearby galaxies that have active nuclei in their centers. The results will appear in the Nov. 9 issue of the journal Science.

Active Galactic Nuclei (AGN) are thought to be powered by supermassive black holes that are devouring large amounts of matter. They have long been considered sites where high-energy particle production might take place.

As I've said earlier, I have an indirect involvement in this via the AirFly collaboration. One of the technique they use at the Auger observatory is to detect the fluorescent signal made by electrons streaming through the atmosphere. These electrons came from showers in the upper atmosphere made by these high energy cosmic rays and gamma rays. What we provide is a way for them to calibrate their signal with the energy of the electrons as they pass through different nitrogen gas pressure.

In any case, it is fun to see how things have progressed, and now we're starting to see results. Let's hope Auger North gets built soon.


Edit: This is the PhysicsWorld review of the report.

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