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Space cuttings "cows" mix. Theoretical explanations are mistakes.


WASHINGTON In the last year of June, a glittering light appeared in the sky, astronomers crazy. After a few months of the investigation, they still do not know what the flash is called "AT2018cow" officially, but they have been named "beef" around the world. Today, scientists presented the ideas of the American Astronomy Society in Seattle on January 11. However, at any time, the astronomer Liliana Rivera Sandoval at Lubeck University of Texas Tech said: "It's very strange."

The cows appeared on telescope observations on June 16, 2018 and then about 200 million light-years ago it was a small galaxy. It is very bright and there was no day. This quick appearance seems to exclude the power of the supernova, as a star usually explodes when the sun shines. Daniel Perley, an astronomer at the John Moores University in Liverpool in the United Kingdom, said: "When we see this phenomenon, we think we'll get started."

The astronomers thought initially what happened to "milk cows", probably in Milky Way, much less than the disaster created by the supernova. The only option is that white dwarfs swallow a star and, occasionally, burns in the process. These events are commonplace in the Milky Way. But the ghostly test of AT2018cow quickly showed that the body of the sky could be in another galaxy above the Earth – this distance would never see white dwarfs.

Perley is a global leader in the rapid response to the telescope, GROWTH, and many telescopes of the network have quickly fixed "cows". Among them, in La Palma, the Canary Islands, Spain and the Palomar Observatory there is a Liverpool telescope. Perley said: "In the first two weeks, we left everything and we watched a night seven times."

Initial observations confirmed that this "cow" was very rare. It does not show the change in the light emitted by the supernova, its brightness continues to grow and the brightness and heat last for almost 3 weeks. "These are supernovae," said Perley.

Sandoval said that in 2018 the "cows" were far away, NASA's Neil Gaines Swift Observatory performed its activities under ultraviolet and X-rays. watching Observations from the orbit show that the celestial body is very bright on both sides of the spectrum. While X-ray flashes changed during the first few weeks, "the spectrum change is not very common." Sandoval said. After 3 weeks, the X-ray signal began to change completely, and the brightness began to decrease.

Many astronomers accept that it is a long and steady event that was fed by a central engine after the initial appearance. But what this engine might be, it is clear. Some believe that this supernova can be unusual, in which the collapse of the nucleus bursts into a star after a star. Others believe that it is an event to destroy the tide – a star is torn by a black hole. But usually in the middle of the galaxy a supermassive black hole is required, and the "cow" is placed on a spiral galaxy. Therefore, it can be said that it may be an intense marital disorder caused by a massive black hole, despite the controversial evidence of the existence of this small black hole. "All the explanations are a problem," Sandoval said.

After discovering four-day "beef", Anna Ho of Technology at the Pasaia Institute visited Mauna Kea's Mamma Array telescope in Mauna Kea, Hawaii. At the ends of the radio spectrum, millimeters of waves are not used to observe conventional expansion objects, since their signals are rapidly retrievable and the telescope can not be captured. And this "cow" is different. "In a few days, it's still very bright," Ho said. "This is the first time we have seen this light source".

This sign shows that the explosive start of the shock waves around dense gas and dust clouds. When this happens, the cloud becomes hot and the waves emit light waves. At the same time, radiation travels through the clouds. The decline in a lower millimeter signal over time indicates that the shock wave has exceeded the outside of the gas cloud.

He stressed that astronomers may find similar sources of light in the future, so, if they look at shock waves, they will provide valuable data on their size, speed, energy, and the surrounding environment. Bob Kirshner, an astronomer at Palo Alto Gordon and Betty Moore Foundation in California, said: "This will tell us what stars have exploded before."

As is often the case, researchers need more data. "There are more dairy products I expect," said Sandoval. (Zhao Xixi)

Chinese Science and Technology Magazine (1st 2019-01-14 2nd International Edition)


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