Low-mass extension of the halo-to-stellar mass relation

Determine whether the halo-to-stellar mass relation for galaxies with stellar masses between log M⋆ = 6 and 9 is elevated relative to the extrapolation of the DESI dwarf-galaxy relation.

Background

The study measures the halo-to-stellar mass relation for DESI dwarf galaxies down to log M⋆ = 7.8 and compares an extrapolation of that relation with individual halo-mass measurements from nearby dwarf-galaxy rotation-curve studies. Two comparison samples appear to lie systematically above the extrapolated DESI relation, while measurements for isolated dwarfs lie approximately between the paper’s extrapolations.

Because the comparison samples may be affected by selection effects, particularly selection for gas-rich systems, the authors do not resolve whether the relation at lower stellar masses is genuinely elevated. The unresolved range extends below the directly probed DESI regime to log M⋆ = 6.

References

Collectively, these tensions suggest that current FDM models face difficulties in simultaneously reproducing the observed properties of LSB systems. That said, given the still limited number of galaxies tested against FDM predictions, as well as the rich theoretical FDM landscape yet to be fully explored, we consider the issue to remain open and worthy of further investigation.

— Probing dynamics of extreme galaxies I. Dark matter content in ultra-diffuse galaxies  (2609.10700 - Bouchè et al., 9 Sep 2026) in Section 5.2, subsection “Fuzzy dark matter”

Therefore, it is unclear whether the $$--$M_\star$ relation between $\log M_\star=6$--$9$ is more elevated than the extrapolation from DESI dwarfs.

— Extending the Stellar-to-Halo Mass Relation to Dwarf Galaxies with DESI DR1  (2609.04351 - Shao et al., 3 Sep 2026) in Section 5.3, “HSMR: Average Halo Masses of Central Galaxies” (subsection labeled sec:hsmr)