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

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^-24 eV ≲ m ≲ 10^-20 eV. The constraints probe the ULDM fraction down to f ≲ 0.3 of the total dark matter.