Search for Neutrinos from Gamma Ray Bursts with the AMANDA Detector

Rellen Hardtke, University of Wisconsin, Madison

Gamma-ray bursts (GRBs) are the most energetic cosmological events in the universe since the Big Bang. During their few seconds of existence, GRBs may produce as much as energy as millions of galaxies.

In the late 1960s, the U.S. Department of Defense and the U.S. Atomic Energy Commission launched a network of Vela satellites to monitor the nuclear test ban treaty by looking for gamma radiation from atomic explosions. Brief, randomly distributed explosions of gamma radiation from space were detected. These "gamma ray bursts" were announced in 1973, and since then, scientists have been trying to explain the physical mechanisms that could create such cataclysmic events.

The Antarctic Muon and Neutrino Detector Array (AMANDA) is a neutrino detector located at the South Pole. Neutrinos, which are chargeless and nearly massless, are notoriously difficult to detect. On occasion, one will interact with rock or ice in the earth and produce a muon. The relativistic motion of the muon creates an electromagnetic shock wave called Cherenkov radiation.

AMANDA consists of hundreds, and eventually thousands, of photomultiplier tubes (PMTs) deployed between one and two kilometers deep in the ice. The AMANDA PMTs detect the Cherenkov radiation from the relativistic muons. By recording the timing and topology of PMTs triggered in an event, we can reconstruct the paths and directions of the muons and neutrinos.

The detection of neutrinos associated with GRBs would provide important information on the physics of GRBs and whether they may be responsible for another astrophysical enigma, ultra high energy cosmic rays.

AMANDA uses data from the Compton Gamma Ray Observatory (CGRO), an orbiting gamma radiation satellite detector, to assist our search for neutrinos associated with GRBs.

The AMANDA detector recorded several hundred gigabytes of raw data in 1997. This poster will describe how that data was filtered for various research goals at the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory. I will also describe how the data filtered for our GRB studies was reconstructed and analyzed at the University of Wisconsin-Madison, and how data from the CGRO satellite was incorporated in our work. The current status of GRB neutrino research will be summarized.

Abstract Author(s): Rellen Hardtke