The Andromeda galaxy ate the lost brother and sister of the Milky Way | Smart news

Once upon a time there were three large galaxies in the local group who were the best friends, Andromeda, the Milky Way and the slightly smaller brother of the Milky Way, M32p. For a long time, the three disks swirled one near the other, sucking matter and other smaller galaxies. But one day, Andromeda was so hungry that she crushed herself on M32p, engulfing her and tearing her apart, leaving behind a trail of cosmic guts. Hannah Devlin at The Guardian reports that scientists have just discovered this galactic murder story by studying the Andromeda halo, and the story will help them refine the science behind the formation of galaxies and fate from our own galaxy. Like our own milky way, Andromeda is a spiral galaxy. But it has some unique features, including a low halo of stars orbiting around and a small but very dense satellite galaxy called M32. The researchers believed that this starry halo was created while Andromeda absorbed hundreds of smaller galaxies over time, leaving behind galactic crumbs. But according to a press release, astronomers using computer models of galaxy formation found that the best explanation for the halo of Andromeda was not the gradual engulfment of small galaxies but a galactic meal giant. And that meant that these remaining stars could be used to rebuild the Andromeda galaxy.

"It was a moment" eureka ", says Richard D & # 39; Souza, astronomer of the University of Michigan, lead author of the newspaper in 19459003 Nature Astronomy . "We realized that we could use this information from Andromeda's outer stellar halo to infer the properties of the larger of these shredded galaxies."

"It's kind of like a child having dinner, then looking down and finding breadcrumbs around," says D & # s Souza to Devlin. "You know what has been eaten." [19659002] Ryan F. Mandelbaum in Gizmodo reports that the model explains a number of Andromeda features.The stars in the Andromeda halo both are about 2 billion years old, just like about a fifth of Andromeda stars proper, suggesting a mbadive galactic collision and an explosion of star-forming activity in the past. The stars in the halo are also composed of elements heavier than hydrogen and helium, just like the super-compact galaxy M32, suggesting that it was once the nucleus of a galaxy absorbed by Andromeda, spitting like a pit

means that the halo and the nucleus are all that remains of M32p, which would have been the third 3rd largest galaxy of our local group, a family of about 50 galaxies in an area of ​​about 10 light-years apart. The galaxy would have been a mbadive lunch, about 20 times bigger than anything our own milky way has ever eaten.

"Astronomers have been studying the local group – the Milky Way, Andromeda and their companions for so long – it was shocking to realize that the Milky Way had a big brother, and we never knew it," he says. Eric Bell, co-author of the University of Michigan, in his release.

The discovery has already upset some of our galaxy training knowledge.For example, according to the publication, it was believed that the merger of two major galaxies would destroy any spiral galaxy and would lead to the formation of an elliptical galaxy, an amorphous galaxy similar to a drop.But Andromeda and its spiral have survived.A study earlier this year also indicated that It had undergone a fusion 1.8 to 3 billion years ago, but instead of swelling in an elliptical galaxy while eating M32p, this study shows that its disk has thickened and the galaxy has undergone mbadive training

Mandelbaum reports that other astronomers say that simulation makes sense, although, of course, the model is just the best guess of what has happened. "Although I find the evidence that they have put together in this very compelling article, it would be worthwhile to have detailed simulations that attempt to follow this model to validate it," says Monica Valluri, professor of 39, astronomy at the University of Michigan

. Devlin reports that the discovery also reveals something about our own destiny. The Milky Way and Andromeda rush back to each other at 248,000 miles per hour and will eventually collide in about four billion years, creating a new galaxy that some have dubbed Milkomeda. "We will be shredded and will be part of the galactic halo," says Dr. Souza. Despite the mbadive collision, the chances that it directly affects the Earth or our solar system are tiny, says physicist Dave Goldberg at i09, since so much of space is, well, empty space. But the worry is misplaced anyway. At the moment of impact, our sun will become a red giant, developing so much that it will have engulfed our planet, cooking all the descendants of humanity that still remain.

Although we are gone, there is still a chance that our beloved galaxy will be more than a simple snack; there is hope that Andromeda will not absorb us as M32p. Previously, astronomers believed that Andromeda was two or three times the size of the Milky Way, but recent research suggests that both galaxies are about the same size, which means that we will have a chance to surpbad ourselves when our spirals will entangle. 19659012] I like this article?
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