Depiction of Antares along with a photo closeup of one of the optical detectors.
(Credit: F.Montanet, CNRS/IN2P3 and UJF for Antares)
A unique astrophysical observatory has taken shape on the ocean floor of the Mediterranean. ANTARES, or the Astronomy with a Neutrino Telescope and Abyss environmental RESearch project, has been fully operational since May 2008 and is in the business of detecting Cherenkov radiation flashes caused by interactions of high energy muon neutrinos with the water in the deep Mediterranean Sea. A joint French-European consortium venture, ANTARES consists of 12 strings of optical detectors each with 25 sensors monitoring the surrounding sea for these elusive flashes. Neutrinos are generated in copious amounts anywhere in the universe that fusion occurs; from the heart of our Sun to supernovae to gamma-ray bursts, millions of neutrinos are zipping through us every second, for the most part, never interacting with baryonic matter. Very occasionally, however, just such an interaction occurs, producing a flash that scientists operating the ANTARES “telescope” hope to detect and trace back. ANTARES also compliments the Ice Cube (the neutrino telescope, not the rapper!) and AMANDA arrays located in the Antarctic, and like those stations, primarily looks for flashes emitted by neutrino emissions coming from up through the bulk of the planet to eliminate cosmic ray flashes occurring over head. ANTARES specialty will be to detect neutrino emissions related to gamma-ray bursts and energetic galactic nuclei. Located at a depth of 2.5 km, it is the first deep sea detector of its kind, and will serve as a proof of concept for a square kilometer array. Interestingly, a pioneering technology known as AMADEUS, or the Antares Modules for the Acoustic DEtection Under the Sea is also piggybacked on ANTARES, which seeks to pinpoint sound waves generated at 10 kHz by neutrino interactions. This would have a greater range of detection out to 5 km versus the visual detection range of 60 meters for the present detectors. Of course, all sorts of ambient noise and luminescent undersea sources will have to be filtered out in the process.
Why study neutrinos? Well, since these fleeting particles travel through just about anything, they allow us to model and predict the goings on of what are otherwise hidden internal sources, like say, the heart of our Sun. As resolution of these arrays get better and better, Neutrino Astronomy is coming into its own… and heck, bizarre astrophysical telescopes are just plain cool!