Dynamical tests of dark matter in Local Group galaxies: shortcomings and new avenues

The distribution of dark matter in the Milky Way and neighbouring Local Group galaxies is an important indicator of the nature of dark matter.

Accurately determining the smooth distribution of dark matter in these galaxies and the degree of clumpiness (abundance of luminous and dark satellites) encodes information about the properties of dark matter and the interplay between the baryonic and dark sectors in the formation and evolution of galaxies.

As well as being auxiliary quantities in interpreting the results of multichannel dark matter searches.

Thanks to significant investments in observational resources by international and, in particular, European countries, we now have access to an enormous amount of detailed, high-quality astronomical data that allow us to view Local Group galaxies as complex systems in interaction with their environment.

The DiaLoGues project will help harvest these exquisite data's full potential in interdisciplinary dark matter searches with a hybrid approach.

On the one hand, we will address biases in the smooth, galactic-scale distribution of dark matter in current chemo-dynamical models of the Milky Way and neighbouring dwarf galaxies.

On the other hand, we will search for peculiar features in the spatial distribution and kinematics of individual stars in Local Group dwarf galaxies, which will then be confronted with signatures of luminous and dark mergers in state-of-the-art hydrodynamical simulations.

In this way, the theoretical link between observations and the accretion history of the host dwarf galaxy will be provided.

DiaLoGues will be a transfer-of-knowledge agent between the astroparticle and astrophysics communities, contributing to the interdisciplinary endeavour to constrain the underlying particle physics model that governs dark matter at the microscopic scales.