Exploring the Local Group with constrained simulations




Center for Theoretical Physics PAS

January 17, 2024 12:30 PM

Exquisite observations of the galaxies in the Local Group – comprising the Milky Way, M31, and a population with lower masses – have enhanced our understanding of various astrophysical processes. In this highly non-linear regime, numerical simulations have proved essential to model how these mechanisms affect the evolution of low-mass galaxies in the unique and dynamic environment of the Local Group. This is best studied in 'constrained' simulations, which embed Local Group analogues in larger-scale structure that closely corresponds to observational proxies. Using the HESTIA suite of such simulations, I explore the properties of low-mass galaxies that can be found ‘in the field’ of the Local Group at the present day. The simulations predict the existence of a population of 'ultra-diffuse galaxies' (UDGs): objects with a stellar content typical of the low-mass galaxies that orbit our Galaxy but with sizes approaching that of the Milky Way. These highly elusive objects could provide useful insights into the nature of dark matter and improve our understanding of the extremes of galaxy evolution. I show that UDGs could account for as much as half of the total population of field galaxies within 2.5 Mpc of the Local Group, and several could be awaiting discovery in Sloan Digital Sky Survey data that have already been collected.

This is a hybrid event:
Room D, the Institute of Physics PAS, Al. Lotników 32/46

Online: Zoom Link, (Passcode: 134595, Meeting ID: 823 8038 0442)