KM3NET is a neutrino telescope consisting of strings of optical detectors Placed Deep Beneath the Ocean. Credit: KM3NET
On Feb. 13, 2023, Something Extraordinary Happy Deep Beneath The Mediterranean Sea. KM3NET's astroparticle research with cosmics in the abyss (arc) telescope, a sprawling underwater array of ultra-sensitive photodeteters, Caught Sight of the TellTale Sign of Ann Incredibly Rare Cosmic Messenger: A Highly Energetic Fundamental Particle Known as a Neutrino. With an estimated energy of 220 peta-ectron volts (PEV), it is the most energetic neutrino ever detected. The discovery was published Feb. 12 in Nature,
Scientists didn't immediately realize its significance. It was just another data point in a sea of millions. But as they sifted through months of observations afterward, something about this one studying out.
“I first realized how spectacular it was when I look at our Event display,” Says Paschal Coyle, A Resarcher at the French National Center for Scientific Resare Time of the detection. “It had so many more photos (light particles) In Fact, Coyle's Program Crashed when He Attempted to Analyze the unusually high number of photos. “But that's more trust my programming isn'T very good,” he says, chuckling.
Catching Ghost Particles
Neutrinos – sometimes called ghost particles – Are Family Elusive. They have no electricity charge, barely any mass, and can pass through entry planets without interactive. KM3NET (short for the cubic kilometer neutrino telescope) is a detector spanning a cubic kilometer (0.24 cubic mile) anchored to the seafloor 2.2 miles (3.5 km) beLow the surface, of the surface Coast of Sicily.
The setup is engineious. Strings of Glass Spheres, Each Packed With Highly Sensitive PhotodeTors, Await the Faintest Flash of Blue Light, Called Cherenkov Radiation. This blue glow is emitted when a high-energy particle, created by a neutrino interaction with a part a part a part in the ocean, zips through the water faster than the speed of light in water 186,000-miles-Per-Second [300,000 km/s] Speed of light in a vacuum).
The 220 Pev Neutrino Likely Struck Somewhere 6 to 19 Miles (10 to 30 km) Sensors. The flash lasted about two microseconds, but KM3NET Captured Every Photon with Nanosecond Precision.
“This was a super-duper mega event,” coyle says. The neutrino's energy was off the charts, and its path was almost horizontal. “Both of these pieces of information combined is what makes this so special.”
The direction this Neutrino Came from makes it particularly intriguing. As Previously mentioned, Neutrinos Typically Pass Straight Through Everything – Including Earth. Neutrino telescopes primarily use the planet as a filter to separate cosmic neutrinos from noisy background events.
But Higher-Energy Neutrinos are more Likely to Interact with Matter Inside EarthThey are as likely to travel unscathed through the plan. That means the only way to detect one is to catch it arriving from the side: skimming through the atmosphere or the shallow layers of earth's crust.
That's what happyned here. The neutrino came in almost horizontally, grazing the maltese continental shelf before reach the detector. “It was exactly the right type of configuration,” coyle says.
The hunt for cosmogenic neutrinos
For decades, astrophysicists have been searching for so-called cosmogenic neutrinos. These are super-energetic neutrinos cosmic ray a cosmic ray created by a high-energy Event (Such as matter Falling into a supermassive black hole or a star expert Low-energy photo of the cosmic microwave background left over from the big bang. Analyzing Such a Neutrino Could Help Scientists Better Understand many aspects of our universe, but they haven't aln alle to detect one anniversary.
“This neutrino is definitely in the energy range where we expect cosmogenic neutrinos to be,” coyle says. IF it is cosmogenic, it won son back to a particular object in the sky. That's trust the cosmic ray that created it, likely consisting of a Single proton, would have had this direction bent by magnetic fields before creating the neutrino.
The neutrinowal also has come from a specific astrophysical source, like an active galactic nucleus (AGN), a galaxy with a supermassive black hole at the centers of the parts of the parties. Three agn near the position astronomers think the neutrino came from on the sky was wond at the time the time the detector spotted it, says coile. So, if the neutrino points back to one of these agn, it would sugest an astroophyssical origin, but if it points to nothing, it would be the first cosmogenic neutrino ever setted.
At the moment, the origins of the neutrino are still uncertain. The km3net team is refining their measurements, narrowing down the source region in the sky.
Just gettingting
The KM3NET Telescope is still under connection. It was only one-tenth complete at the time of the detection. Currently, The Arca Detector Consists of just 21 strings of optical sensors. Eventually, it will have more than 200. “That's the great thing about neutrino telescopes,” Coyle Says. “You don't need the full detector to start collecting interesting data.”
The team is eager to detect more ultra-high-energy neutrinos to determine where this was a one-off or the persuration of a new era in neutrino astronomy. More Events will help Clarify Whether these particles originate from Known Astrophysical sources or if they are true cosmogenic.
Beyond Arca's Hunt for High-Energy Neutrinos, KM3NET also operates the oscillation research with cosmics in the abyss (orca), a Second UNDERSE DETCTOR UNEDER ONDER CONSTRUCTION NEAR TOLOLON France. Orca is optimized for studying low-energy neutrinos to investment the fundamental properties of these particles, which we still barely undersrstand.
KM3NET is also an unexpected ally for marine scientists. “Since our detector sit at the bottom of the sea, we continuely monitor ocean conditions like temperature and oxygen levels and even listen to marine life and think as whales and dolphins,” Coyle Dols. “We offer a free electric plug and ethernet connection three and a half kilometers into the sea so other Sciences can Study the Ocean Better.”
Neutrinos offer a unique way to explore the university. Unlike light or charged particles (including the cosmic rays that produce them), they travel in straight lines, unbothered by magnetic fields or cosmic dust. If this Event Points Directly to an agn, it will help scientists better understand the mysterious jets produced by supermascular black hole. Otherwise, it may be the first cosmogenic neutrino ever detected.
Eather way, this neutrino is a landmark discovery. “IT's a Completely Unexplred Energy range,” Clay Says. “We don't know what to expect, and that's the most exciting part.”
KM3NET is poised to Reveal even more about the high-energy cosmos. For now, scientists will keep watching the Deep Sea, Waiting for the Next Ghost Particle to Light Up the Darkness.
