New Simulations Show How Galactic Centers Grow Together

A team of researchers from the Leibniz Institute for Astrophysics Potsdam (AIP) conducted a high-resolution hydrodynamical simulation to study the formation and evolution of galactic centers. The simulation revealed that nuclear star clusters and stellar discs found in the inner core of galaxies are not independent processes, as previously thought. The study, published in Astronomy & Astrophysics, shows that these features grow together, forming a coherent evolutionary link. The simulation demonstrated that a barred galaxy, like the Milky Way, can naturally form both nuclear star clusters and nuclear stellar discs simultaneously, with the stellar bar playing a central role in funneling gas inward to feed both structures from the same reservoir.

The simulation also shows that the galaxy’s stellar bar acts like a cosmic conveyor belt, channeling gas inward to feed both structures simultaneously. Over billions of years, hundreds of millions of solar masses' worth of stars form in the galactic center. The results explain why previous observations failed to find a clear connection between nuclear star clusters and nuclear stellar disks. The simulation directly reveals an evolutionary link between their formation, showing that they grow together. The results also show that the structural relationship between the two processes naturally evolves, with the relative masses and sizes of the cluster and disk beginning to differentiate during periods of sustained growth.

The simulation included dark matter, which played a crucial role in the results. The team’s model allows for a realistic bar that evolves in time and naturally forms nuclear structures. The model also exhibits a 'dark gap' around the bar region, which is found in many observations and is known as evidence of the interaction between stars and dark matter by the rotation of the stellar bar. These findings could expand our understanding of the connection between galactic components, helping astronomers interpret future observations.

AI-generated summary of the original article — see the source for the full story.