Creating a galaxy lacking dark matter in a dark matter-dominated universe

We use hydrodynamical cosmological simulations to show that it is possible to create, via tidal interactions, galaxies lacking dark matter (DM) in a DM-dominated universe. We select dwarf galaxies from the NIHAO project, obtained in the standard cold dark matter model and use them as initial conditions for simulations of satellite-central interactions. After just one pericentric passage on an orbit with a strong radial component, NIHAO dwarf galaxies can lose up to 80 per cent of their DM content, but, most interestingly, their central (approximate to 8 kpc) DM-to-stellar mass ratio changes from a value of similar to 25, as expected from numerical simulations and abundance matching techniques, to roughly unity as reported for NGC 1052-DF2 and NGC 1054-DF4. The stellar velocity dispersion drops from similar to 30 km s(-1) before infall to values as low as 6 +/- 2 km s(-1). These, and the half-light radius around 3 kpc, are in good agreement with observations from van Dokkum and collaborators. Our study shows that it is possible to create a galaxy without DM starting from typical dwarf galaxies formed in a DM-dominated universe, provided they live in a dense environment.

Automated summary

Through simulations, it has been shown that dwarf galaxies can lose up to 80% of their dark matter content and see a significant change in the dark matter-to-stellar mass ratio after interactions with central galaxies. These findings align with observations of NGC 1052-DF2 and NGC 1054-DF4.