Hubble peers through the mysterious shells of this giant elliptical galaxy

(ORDO NEWS) — Look at the latest image provided by the Hubble Space Telescope. It depicts a huge elliptical galaxy called NGC 474, which lies about 100 million light-years away.

In size, it is about two and a half times the size of our Milky Way galaxy, it is a real giant. Note its strange structure – mostly featureless and almost round, but with layered shells wrapped around a central core.

Astronomers want to know what led to the formation of these shells. Perhaps the answer lies in what this galaxy represents: a vision of the future of the Milky Way and the Andromeda galaxy.

The Fate of the Milky Way: When Galaxies Collide!

Galaxies change over time. More than 13 billion years ago, the first of them were small pieces of matter. They merged, forming ever larger structures. This process of mergers and acquisitions continues to this day.

It affects the “look” of the galaxy and diversifies its stellar population. Our own Milky Way is part of this process. He is currently cannibalizing the Sagittarius dwarf galaxy.

It has also merged or swallowed up between 5 and 11 smaller galaxies during its lifetime.

Astronomers already know that the Milky Way will continue to participate in the process of merging galaxies.

In about 4.5-5 billion years, it will begin to merge with the neighboring Andromeda galaxy (M31). Of course, over time, M31 will move much closer to us.

As an added bonus, the galaxy Triangulum (M33) may take part in this galactic dance.

For those who follow such events, this will happen around the time the Sun runs out of hydrogen in the core and begins to turn into a red giant. So it will be an interesting time. Mark your calendars.

NGC 474 predicts the future of the Milky Way

Hubble peers through the mysterious shells of this giant elliptical galaxy 2
NASA, ESA and D. Carter/Liverpool John Moores University; image processing: G. Kober/NASA Goddard/Catholic University of America

NGC 474 is very similar to what astronomers think the Milky Way and Andromeda will look like after their merger. They will no longer be two beautiful spirals. Instead, their gravitational interaction will result in the formation of an almost featureless elliptical galaxy.

How will it happen? As two galaxies approach each other, the strong gravity of each will distort their shapes. Giant streams of gas and dust will be pulled out of every galaxy. Central shells of matter may even form, as in NGC 474.

In addition to all this activity, there is another sign of merger: stellar flare nodes. These are the places where stars form after a merger.

The activity pushes clouds of gas and dust towards each other, eventually giving rise to many hot, young stars. This will continue as long as there is enough material in the star formation nursery.

Eventually, the burst of star birth will slow down and stop. As a result, the new galaxy will take on a rather boring elliptical shape.

Here’s what, in a nutshell, happened to NGC 474. And so is the fate of Milkdromeda: a (probably) faceless elliptical that was once two beautiful spiral galaxies.

Explanation of these shells in NGC 474

In the case of NGC 474, astronomers have several theories about why it has these strange shells. One of them is that billions of years ago it interacted with another galaxy. This led to the formation of shells in a process similar to throwing a stone into a pond and watching the ripples radiate from it.

NGC 474 is not the only galaxy with shells resulting from a collision. Approximately 10 percent of all elliptical stars have such features. This may be a clue to the history of their formation and merger, which astronomers will be studying.

There is another interesting point about these shell galaxies. While most elliptical galaxies are found in clusters, these strange orbs occupy relatively empty regions of space.

Perhaps they could become cannibals for neighboring galaxies and thus cleanse their neighborhoods from galactic competition.

Other theories about NGC 474

Hubble peers through the mysterious shells of this giant elliptical galaxy 3
DES/DOE/Fermilab/NCSA & CTIO/NOIRLab/NSF/AURA Acknowledgments: Image Processing: DES, Jen Miller (Gemini Observatory/NSF’s NOIRLab), Travis Rector (University of Alaska Anchorage), Mahdi Zamani, and Davide de Martin

It is also possible that NGC 474 is taking gas from neighboring NGC 470.

Another idea is that the shells could be caused by a collision with a very gas-rich galaxy. Not only did they meet once, but they had a second encounter that led to their final merger.

The shells are evidence that the galaxy merged long ago. In the Hubble image, you can see in more detail the central region and these mysterious shells.


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