ANTARES (telescope)

ANTARES (Astronomy with a Neutrino Telescope and Abyss environmental RESearch project) is a neutrino detector resting 2.5 km beneath the Mediterranean Sea near Toulon, France. It was created to find and watch the flow of tiny particles called neutrinos that come from space, especially from the southern part of the world. This helps scientists learn more about the universe.

ANTARES works together with another big detector called IceCube located at the South Pole. While IceCube looks at neutrinos from both sides of the Earth, ANTARES focuses on the southern sky. This teamwork gives a fuller picture of what is happening far away in space.

Construction and operation of ANTARES lasted for 16 years, and it stopped collecting new data in February 2022. There are other similar projects nearby, such as the Greek NESTOR telescope and the Italian NEMO telescope, though these are still in their early planning stages. ANTARES is also recognized as an experiment by the famous research organization CERN.

Design

ANTARES is a special telescope placed 2.5 kilometers deep in the Mediterranean Sea near Toulon, France. It has twelve long strings, each about 350 meters long, holding special tubes called photomultiplier tubes. These tubes can spot a special kind of light called Cherenkov radiation.

When rare neutrinos from space pass through the water, they can create particles called muons. ANTARES uses these muons to learn about neutrinos coming from the southern part of the sky. Unlike other neutrino telescopes in ice at the South Pole, ANTARES uses water, which helps it see more clearly. However, water also has more natural light sources, so ANTARES needs smart methods to focus on the important signals.

Construction history

Construction of ANTARES finished on May 30, 2008, two years after the first part was placed. Testing started in 2000. Important tools like a seismometer were set up in 2005. The first line of special tubes was moved into place in February 2006. More lines were added through 2006 and 2007, making ANTARES the largest neutrino telescope in the Northern Hemisphere, passing the Baikal neutrino telescope. By May 2008, the detector was fully set up with all its parts.

The work to place and connect the detector was done with help from the French oceanographic institute, IFREMER, using the ROV Victor, and sometimes the submarine Nautile.

The detector stopped collecting data and was taken apart in 2022.

Experimental goals

The ANTARES project works together with the IceCube Neutrino Observatory in Antarctica. Both projects use similar methods to detect neutrinos, but ANTARES looks toward the Southern Hemisphere. Because it is located in the Mediterranean Sea, ANTARES is especially good at finding neutrinos with energies below 100 TeV from the southern sky. This area includes many stars and other objects that give off neutrinos.

ANTARES can detect neutrinos from very powerful cosmic events, with energies ranging from 10¹⁰ to 10¹⁴ electronvolts, which is from 10 GeV to 100 TeV. Over time, it might help create a map showing where these neutrinos come from in the Southern Hemisphere. Scientists are especially excited about finding specific places in the sky that give off neutrinos, which could also be studied using other tools like the HESS telescope in Namibia.

Besides studying cosmic neutrinos, ANTARES can also help solve big questions in physics. For example, it might look for signs of dark matter near the Sun or the Galactic Center. This work complements other experiments looking for dark matter, such as DAMA and CDMS, as well as studies at the LHC. ANTARES might also detect other unusual particles, like nuclearites or magnetic monopoles.

Results

The first neutrino detections were reported in February 2007.

Using data collected over six years, scientists looked for sources of neutrinos coming from the center of our galaxy but did not find any. They also measured how neutrinos change as they travel through the Earth's atmosphere.

Additional instrumentation

Besides the main tool for finding tiny particles called neutrinos, the ANTARES project also has special tools to study the deep sea. These tools can measure things like salt in the water, oxygen levels, and how the sea moves. There is also a camera to watch glowing sea creatures. The information from these tools helps both the ANTARES project and scientists who study the ocean.

ANTARES also has a special sound system to help line up its equipment underwater. There is an extra sound project called AMADEUS, which uses special underwater microphones. This project helps scientists see if they can use sound to find neutrinos in the deep sea.