Abundance matching with the mean star formation rate: there is no missing satellites problem in the Milky Way above M200 ∼ 109 M⊙
Abstract
We introduce a novel abundance matching technique that produces a more accurate estimate of the pre-infall halo mass, M200, for satellite galaxies. To achieve this, we abundance match with the mean star formation rate, averaged over the time when a galaxy was forming stars, <SFR>, instead of the stellar mass, M∗. Using data from the Sloan Digital Sky Survey, the GAMA survey and the Bolshoi simulation, we obtain a statistical <SFR>-M200 relation in Λ cold dark matter. We then compare the pre-infall halo mass, M^abund_{200}, derived from this relation with the pre-infall dynamical mass, M^dyn_{200}, for 21 nearby dSph and dIrr galaxies, finding a good agreement between the two. As a first application, we use our new <SFR>-M200 relation to empirically measure the cumulative mass function of a volume-complete sample of bright Milky Way satellites within 280 kpc of the Galactic centre. Comparing this with a suite of cosmological `zoom' simulations of Milky Way-mass haloes that account for subhalo depletion by the Milky Way disc, we find no missing satellites problem above M200 ∼ 109 M⊙ in the Milky Way. We discuss how this empirical method can be applied to a larger sample of nearby spiral galaxies.
- Publication:
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Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 2019
- DOI:
- arXiv:
- arXiv:1807.07093
- Bibcode:
- 2019MNRAS.487.5799R
- Keywords:
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- galaxies: abundances;
- galaxies: dwarf;
- galaxies: haloes;
- galaxies: kinematics and dynamics;
- cosmology: observations;
- dark matter;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 15 pages, 7 figures. Final version accepted for publication in MNRAS. The methodology has been substantially clarified and improved throughout, including a significantly expanded method section and two new Figures that explain how we derive the cumulative <