The Simba Cosmological Galaxy Formation Simulations

The Simba Cosmological Galaxy Formation Simulations

Creating accurate models of our Universe is one of the great quests of humankind, going back to the ancient Greeks, through to Copernicus, Galileo, and Einstein. In recent years, huge progress has been made in developing physical models that connect the early conditions we see shortly after the Big Bang with the present-day population of galaxies, clusters, and intergalactic gas that we see around us today. Owing to the complex and highly nonlinear nature of gravitational collapse and radiative processes, supercomputer simulations play an increasingly critical role in developing models to explain why the Universe looks the way it does.

The Simba simulations are a next-generation suite of galaxy formation models, run on Cosma-7 at Durham. Simba includes unique physical modules that address some of the most pressing questions in modern galaxy formation theory, such as the growth of supermassive black holes and their impact on their host galaxy, and the formation and evolution of dust grains within a cosmological context. Simba predictions are in remarkably good agreement with a wide range of galaxy demographic properties, and have elucidated new ways in which galaxies and black holes interact with their surrounding cosmic ecosystems to shape the observable properties of both. Simba represents our most comprehensive and faithful view yet of the so-called baryon cycle that drives the formation and evolution of galaxies like our own Milky Way over cosmic time.

Simba has had a major impact on the community since its release in July 2019, with 18 publications as of June 2020 based primarily on Simba data, and over 30 active projects currently listed on the Simba pbworks page. The first annual Simba team meeting was held in February 2020, with over 30 attendees representing 17 institutions from 5 countries, demonstrating the global impact of Simba. Simba is gearing up for a public data release in the Fall, which will further widen the user base and establish it among the pre-eminent cosmological galaxy formation simulations today.