Galaxies come in different shapes and sizes. The Milky Way, for example, is a spiral galaxy because of the way stars, dust, and gas spiral from the center of the galaxy.
But spiral galaxies like ours are surprisingly rare in our galactic neighborhood, and astronomers have wondered why since the 1960s.
Now they finally have an answer, according to a new study published in the peer-reviewed journal Nature Astronomy earlier this month.
‘Brilliant and stunning collection of galaxies’: Here are the first pictures from the Euclid telescope
A turbulent past
Using a supercomputer, researchers have turned back the clock to about 13.8 billion years ago, when our galaxy and those around it were just beginning to form.
Researchers have simulated the evolution of our galactic neighborhood to see what might have happened over billions of years to make spiral galaxies appear so rarely at our end of the cosmos.
They have found evidence of a turbulent past. The simulation shows that galaxies in dense clusters, like the one the Milky Way calls home, experienced frequent collisions and mergers.
In Search of Dark Matter: Pulsars in the Milky Way
When galaxies collide
When galaxies merge, they can form an entirely new type of galaxy. For example, when two spiral galaxies collide, it is believed to create a so-called elliptical galaxy.
This is what both observations of our nearby Universe and simulations show: In our galactic neighborhood, there are many elliptical galaxies but very few spiral galaxies, suggesting that our Milky Way somehow survived a chaotic scenario of galactic collisions during the age of The universe.
“Our simulation reveals intimate details of galaxy formation, such as the transformation of spirals into ellipticals through galaxy mergers,” co-author Carlos Frank of Durham University’s Institute for Computational Cosmology said in a statement.
Astronomers with a discovery: At the center of the Milky Way is a large black hole
Source: Business Insider