They find evidence of “cannibalism” in the Andromeda galaxy.

A team led by an astrophysicist at the University of Sydney has found evidence that galaxy neighbor Andromeda he is a cannibal who grows up at colossal banquets.

“A few years ago we discovered that on the outskirts of the city of Andromeda there was a signal in the objects that revolved around him that galaxy were not ‘grazed’ but ate large quantities on two separate occasions,” lead author Professor Geraint Lewis of the University of Sydney said in a statement.

“This new result gives a clearer picture of how our local universe formed: it tells us that in at least one of galaxies large, this sporadic feeding has taken place galaxies small”.

Evidence of Andromeda’s “cannibalism”

Research results – available on the preprint server arXiv and will be published in Royal Astronomical Society Monthly Notices– based on the discovery of the structure of stars known as globular clusters, in Andromeda which originated outside galaxy. Professor Lewis called this the Dule structure, derived from the Welsh expression “black stream”.

The Dule structure is the remnants of a colossal feeding in the “recent” past, a dark stream illuminated by star clusters that spin like no other in the world. Andromeda. He provides evidence that galaxies they grow by “eating” smaller systems, and the data obtained diverge from the calmer picture of galactic growth.

“This leads to the next question, what was actually eaten? Because it doesn’t look like it was one thing, it looks like it was a collection of things that were slowly being torn apart,” Professor Lewis said. “In recent decades, we have realized that galaxies they grow by eating smaller systems, so small galaxies they fall and eat them, it’s galactic cannibalism.”

Andromeda It has the signatures of two major food events. Approximate time scales show that the “recent” feast took place somewhere in the last 5 billion years, while the older one was closer to 8-10 billion years ago. The universe itself is 13.8 billion years old, meaning that two separate events could have happened when matter in the universe was closer together and more densely concentrated.

“We know that when it was born in the Big Bang, the Universe was faceless, and today it is full galaxies. Were these galaxies born fully formed or did they grow up?” Professor Lewis said.

He teaches us the behavior of galaxies

Astrophysicists such as Professor Lewis study Andromeda to better understand how our own Milky Way evolved. The point of view from Earth makes it difficult to visualize our galaxy because we are sitting inside it, which obscures the observations, but the distance from Andromeda this gives scientists the advantage of a “bird’s eye view”.

It is not clear how the Milky Way fed, but the picture emerges in Andromeda with a clear caption: big feasts and accelerated growth. Since the Milky Way is a similarly sized spiral galaxy, the study could paint a picture of what our galaxy did to reach its massive size.

“We want to know if the Milky Way did the same or differently. Both have interesting implications for the overall picture of star formation.” galaxiesProfessor Lewis said. “At some level, we want to create a more accurate clock that will tell us when these events happened, because that’s what we need to include in our models of plant evolution. galaxies”.

He and his colleagues analyzed data on the velocities and chemical composition of the globular clusters that make up the Dule structure and obtained a two-dimensional representation. The next step is to understand distances, which will allow researchers to build history in three dimensions.

“This will allow us to calculate the orbits where everything is going, and then we can start turning back the clock and see if we can get this consistent picture of when something fell,” he said.

“We couldn’t name it as an object type galaxy, because we don’t really know if the signature we’re seeing is the result of interrupting one large object, or seven interrupted smaller objects. That’s why we call it structure and not galaxy in particular” (Europa Press).

We recommend you METADATA, an RPP technology podcast. News, analytics, reviews, recommendations and everything you need to know about the tech world.