Galactic rotation curves versus ultralight dark matter: A systematic comparison with SPARC data

Abstract

We look for and place observational constraints on the imprint of ultralight dark matter (ULDM) soliton cores in rotation-dominated galaxies. Extending previous analyses, we find a conservative constraint which disfavors the soliton-host halo relation found in some numerical simulations over a broad range in the ULDM particle mass $m$. Combining the observational constraints with theoretical arguments for the efficiency of soliton formation via gravitational dynamical relaxation and assuming that the soliton-halo relation is correct, our results disfavor ULDM from comprising 100% of the total cosmological dark matter in the range ${10}^{\ensuremath{-}24}\text{ }\text{ }\mathrm{eV}\ensuremath{\lesssim}m\ensuremath{\lesssim}{10}^{\ensuremath{-}20}\text{ }\text{ }\mathrm{eV}$. The constraints probe the ULDM fraction down to $f\ensuremath{\lesssim}0.3$ of the total dark matter.