Astronomers understand why there are so few spiral galaxies in our neighborhood

The supergalactic plane is a type of massive structure that extends for about a billion light years. A structure made up of many giant clusters of galaxies and thousands of individual galaxies. Mostly elliptical galaxies. And only a few rare spiral galaxies are like our Milky Way. This observation is surprising enough to be on the list of “Cosmic Anomalies” Founded by cosmologist and 2019 Nobel Prize winner in Physics, Professor Jim Peebles.

A “cosmic anomaly” explained by simulations.

An anomaly that, for the Cosma 8 supercomputer of the Sibelius program – for simulation beyond the local universeUnderstand, “simulations beyond our local universe” – not one at all. Unlike most cosmological simulations, which consider random regions of our universe, Sibelius aims to reproduce observed structures with precision. And that’s what they did with regard to the supergalactic plane.

Taking a closer look, astronomers from Durham University (UK) and the University of Helsinki (Finland) discovered that the secret to the surprising structure of the supergalactic plane was hidden in the contrasting environments inside and outside this particular region.

Spiral galaxies that become elliptical galaxies

in the magazine nature astronomyResearchers report that, in dense galaxy clusters in the supergalactic plane, galaxies experience frequent interactions, collisions, and mergers with other galaxies. All this turns spiral galaxies into elliptical galaxies, smooth galaxies with no obvious internal structure or spiral arms. This also leads to the growth of the supermassive black hole. On the other hand, away from the plane, galaxies may evolve in relative isolation, helping them preserve their spiral structure.