Do dwarf-satellite haloes follow a common surface-density scaling relation?

Cosmological simulations test a halo surface-density measure defined at the radius of maximum circular velocity.

Universal Dark Halo Scaling Relation for the Dwarf Spheroidal Satellites

Universal Dark Halo Scaling Relation for the Dwarf Spheroidal Satellites. Hayashi, Kohei; Ishiyama, Tomoaki; Ogiya, Go; Chiba, Masashi; Inoue, Shigeki; Mori, Masao, Astrophysical Journal, 843, 97 (2017).

arXiv:1703.02604 Publication · DOI

Approach

Simulated subhaloes of Milky Way-sized hosts are compared with halo constraints for Milky Way and Andromeda dwarf spheroidals, including their orbital histories.

Main result

Surface densities agree with the observed satellite estimates. Subhaloes tend to evolve along a relation between maximum circular speed and its radius despite differing mass histories.

Scientific implications

This identifies a structural regularity that can connect dwarf dynamics with cosmological halo evolution.

Scope and limitations

The inference about limited baryonic modification is based on this comparison; it does not show that feedback is negligible for every aspect of dwarf galaxies.