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arXiv · 1811.00553

A constant characteristic volume density of dark matter haloes from SPARC rotation curve fits

Pengfei Li·Federico Lelli·Stacy S. McGaugh·Nathaniel Starkman·James M. Schombert
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Abstract

We study the scaling relations between dark matter (DM) haloes and galaxy discs using 175 galaxies from the SPARC database. We explore two cosmologically motivated DM halo profiles: the Einasto profile from DM-only simulations and the DC14 profile from hydrodynamic simulations. We fit the observed rotation curves using a Markov Chain Monte Carlo method and break the disc-halo degeneracy using near-infrared photometry and $Λ$CDM-motivated priors. We find that the characteristic volume density $ρ_{\rm s}$ of DM haloes is nearly constant over $\sim$5 decades in galaxy luminosity. The scale radius $r_s$ and the characteristic surface density $ρ_s\cdot r_s$, instead, correlate with galaxy luminosity. These scaling relations provide an empirical benchmark to cosmological simulations of galaxy formation.

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Pengfei Li, Federico Lelli, Stacy S. McGaugh, Nathaniel Starkman, James M. Schombert. 2018-11-01. A constant characteristic volume density of dark matter haloes from SPARC rotation curve fits. https://doi.org/10.1093/mnras%2Fsty2968

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