Title: Dynamical tests of dark matter and galaxy formation theories in the Milky Way and beyond

New data from Gaia and SDSS have challenged the long-held conception of the Milky Way as an equilibrium system, instead painting a picture of a time-dependent Galaxy continually transformed by its cosmological environment. This new picture is as much opportunity as challenge, requiring the development of new approaches to study the dynamics of disequilibrium while offering a panoply of new avenues for tests of dark matter and galaxy formation. I will discuss how connecting state-of-the-art cosmological simulations of galaxy formation with new numerical techniques for modeling the dark and baryonic content of galaxies on one hand, and with well-tested methods for synthetic observations on the other, have opened a new route to understanding the interplay between dark matter and baryons during galaxy assembly. This approach will be extended to nearby galaxies in the decade to come, leading to powerful constraints on theories of both dark matter and galaxy formation.

Research image Caption: Density of dark matter in a simulated Milky Way-like galaxy interacting with a satellite galaxy similar to the Large Magellanic Cloud (pink star), with white and blue denoting low density and yellow and red denoting high density, as the background colormap. Contours highlight the part of the density distribution that is evolving coherently as a quadrupole—the expected symmetry for the response to a galaxy merger according to analytical theory. The strongest contribution to the evolving quadrupole signal comes from the large scale filaments of dark matter feeding the Milky Way, while the merger produces a smaller effect in the inner galaxy during its closest approach (pictured).

Hosts: Lina Necib, Xuejian ‘Jacob’ Shen                                                                                                                                                                                  via Zoom