Recent studies have provided new understanding of the unique distribution of galaxies in local superclusters. This study, using advanced SIBELIUS simulations, revealed that galaxy types naturally segregate due to differences in environmental conditions inside and outside the supergalactic plane. This discovery validates the standard model of dark matter, challenges previous assumptions about anomalies in the universe, and significantly contributes to our understanding of galaxy evolution. Credit: SciTechDaily.com
Why are giant supergalactic planes filled primarily with one type of galaxy? This long-standing astronomical mystery may finally be solved.
of milky way Our cosmic home galaxy lies within a vast expanse known as a local supercluster. This massive structure contains many huge galaxy clusters and many individual galaxies. The supercluster, which has a pancake-like structure and spans nearly a billion light-years, has been nicknamed the supergalactic plane.
Most galaxies in the universe fall into one of two categories. One is an elliptical galaxy made up primarily of old stars and usually contains a very massive central black hole, and the other is a disk galaxy with active star formation and a spiral structure similar to the Milky Way. Method. Both types of galaxies are also found in local superclusters, but while bright elliptical galaxies are abundant in the supergalactic plane, bright disk galaxies are noticeably absent.
Cosmic anomalies cast doubt on the standard model of cosmology
This unusual separation of galaxies in the local universe has been known since the 1960s and featured prominently in a recent list of “cosmic anomalies” compiled by renowned cosmologist and 2019 Nobel Prize winner Jim Peebles. ing.
Now, an international team led by astrophysicists Tir Sawala and Peter Johansson from the University of Helsinki appears to have found an explanation.In an article published in natural astronomyThey show how the different environments found inside and outside the supergalactic plane naturally result in different distributions of elliptical and disk galaxies.
![super galactic plane graphics](https://scitechdaily.com/images/Supergalactic-Plane-Graphic-777x392.jpg)
In the supergalactic plane on the equator shown in the photo, galaxies frequently interact and merge, forming giant elliptical galaxies. In contrast, galaxies far from the surface can evolve relatively isolated and maintain a disk-like structure.Credit: Til Sawala
“In dense galaxy clusters located in the supergalactic plane, galaxies frequently experience interactions and mergers, which lead to the formation of elliptical shapes and the growth of supermassive black holes. In contrast, far from the plane “Galaxies can evolve in relative isolation, which helps maintain their spiral structure,” says Thiru Sawala.
The research team used the SIBELIUS (Simulations Beyond The Local Universe) simulation, which tracks the evolution of the universe over 13.8 billion years, from the beginning of the universe to the present. This was run on a British supercomputer and his CSC Mahti supercomputer in Finland.
Implications and future directions in cosmology
While most similar simulations consider random patches in the universe that cannot be directly compared to observations, the SIBELIUS simulation aims to accurately reproduce the observed structure, including local superclusters. The final simulation results are in remarkable agreement with the observations.
“By chance, I was invited to a symposium honoring Jim Peebles last December, where he raised this question in his talk. And I realized that I had already completed a simulation that might contain the answer. I realized that,” comments Til Sawala. “Our study shows that known mechanisms of galaxy evolution also operate in this unique cosmic environment.”
At the University of Helsinki’s Kumpula Campus, next to the Department of Physics, there is a large statue showing the distribution of galaxies within the Local Supercluster. This research was started 20 years earlier by British cosmologist Carlos Frenk, one of the co-authors of this new study. “The distribution of galaxies within the local supercluster is certainly noteworthy,” Frenk says of the new results. “But that’s not an anomaly. Our results show that the standard model of dark matter can produce some of the most remarkable structures in the universe.”
Reference: “A distinct distribution of elliptical and disk galaxies across local superclusters as a ΛCDM prediction” by Til Sawalha, Carlos Frenk, Jens Jachet, Peter H. Johansson, and Guillem Laveau, 2023. 11 20th of the month, natural astronomy.
DOI: 10.1038/s41550-023-02130-6