Astronomers say this could be the largest structures in the universe

Astronomers have discovered the beginnings of what they say is a gigantic cosmic pileup that could someday form one of the largest structures in the universe. In a study published in the journal Nature, a team of international scientists used computer simulations of the galaxies to predict that, over time, this massive cluster will assemble to become the biggest structure in the modern universe. The research, published in the journal Nature, says the so-called protocluster or group of galaxies is 12.4 billion light years away -- suggesting its light began travelling to Earth when the universe was 1.4 billion years old. “Having caught a massive galaxy cluster in throes of formation is spectacular in and of itself,” researcher Scott Chapman, an astrophysicist at Dalhousie University in Halifax, said in a statement..

“But, the fact that this is happening so early in the history of the universe poses a formidable challenge to our present-day understanding of the way structures form in the universe.”

Chapman said until now, astronomers had theorized that protoclusters as large as this one would have taken much longer to form. One of the researchers, astrophysicist Scott Chapman of Dalhousie University, says the discovery challenges conventional understanding of how structures form in the universe since it happened so quickly and in a space only about three times the size of the Milky Way. Astronomers call the object a galactic protocluster, a precursor to the type of enormous galaxy clusters that are the largest-known objects in today's universe. Tim Miller, a doctoral candidate at Yale University and co-author on the paper, said: “How this assembly of galaxies got so big so fast is a bit of a mystery, it wasn’t built up gradually over billions of years, as astronomers might expect.”

Computer simulations indicate that, over the next billion years or so, the 14 galaxies will merge into one giant elliptical galaxy surrounded stars and cosmic dust. "We often get excited when we find just two galaxies like this grouped together, because each one is already quite unusual and rare compared to 'normal galaxies', forming stars several hundreds or thousands of times faster than the Milky Way.
Astronomers detect light from 14 colliding galaxies. Due to the distances involved, the light comes from events which occurred around 12 billion years ago.