New detector detects gamma rays from amazing cosmic ray sources


Mt. Heidi (AP), China — Astrophysicist Cao Zhen opens a steel hatch on the windswept Tibetan Plateau and descends a ladder into total darkness. His flashlight picks out a boat that floats in a pool of purified water above thousands of glittering orbs the size of a beach ball.

He is in the $ 175 million observatory and has already discovered intriguing astronomers even before the observatory was technically completed. Gamma-ray bursts from space may one day help explain how matter is created and distributed throughout the universe.

The largest device of its kind, the Large-Scale High-Altitude Air Shower Observatory, has detected a dozen sources of ultra-high-energy gamma rays. Research From what Cao calls “many hotspots” in the journal Nature, in our Milky Way galaxy.

Such high-energy gamma rays have never been detected, and it is known that these rays can be generated not only from dying stars, but also inside giant young stars. ..

“These results are truly amazing, some of the most exciting I’ve ever seen,” said Alan Watson, an astrophysicist working at the Pierre Auger Observatory in Argentina.

Cao’s team tracked 530 high-energy gamma rays up to 12 sources, including a giant cluster of young stars called the cocoon in Cygnus and an interstellar cloud called the Crab Nebula.

Gamma rays are a type of extreme radiation produced by the hottest and brightest explosions in the universe, such as when a large star explodes. Those detonations also create the problems that make up the planet, and everything that lives on the planet, including us. Of all the electromagnetic waves in the universe, gamma rays have the smallest wavelength and the highest energy. They can release more energy in 10 seconds than our sun in 10 billion years.

LHAASO’s purified water pool rowed by Cao contains fragments of elementary particles (the “air shower” in the name of the observatory) created when high-energy particles called gamma rays and cosmic rays collide with the Earth’s atmosphere. To measure.

Shrapnel contains a mysterious particle called Muon It can be seen as a faint blue flash known as Cherenkov radiation in the dark waters of the observatory. An array of 3,120 beach ball-sized globes contains a small sensor that measures radiation.

“These gamma rays can be traced back to the source of the sky,” said Cao Cao, who wore a blue scrub to keep the water clean. “We can find something new.”

LHAASO is one of dozens of devices on Earth and in orbit, suspended inside Antarctic ice tunnels and toaster-sized satellites, how substances such as carbon, oxygen, and iron can be found. I’m trying to understand what happened.

Located near Mount Heidi, 4,400 meters high (14,500 feet high), it is an individual that can study a variety of phenomena, including cosmic rays and high-energy subatomic particles that scientists believe come from the same source as gamma rays. Accommodates the equipment of. Cosmic rays are like sparks from a giant crucible. Each contains spots of material from the forging process. Gamma rays are like light from a shining hearth. By studying both, the observatory can learn more about what produced them.

The Chinese Observatory offers “unprecedented sensitivity,” said Abi Loeb, an astrophysicist at Harvard University.

However, it has not been completed yet. By the end of June, Cao said equipment including 5,195 electromagnetic detectors, 1,188 muon detectors and 18 Cherenkov telescopes would be installed.

“The results justify a really great effort,” Watson said of the new discovery. “This is just the tip of the iceberg.”

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Associated Press video producer Olivia Chan of Heidi Mountain and science writer Seth Borenstein of Washington contributed to this report.

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