Subhalo statistics of galactic halos: beyond the resolution limit

Abstract

We study the substructure population of Milky Way (MW)-mass halos in the $\Lambda$CDM cosmology using a novel procedure to extrapolate subhalo number statistics beyond the resolution limit of N-body simulations. The technique recovers the mean and the variance of the subhalo abundance, but not its spatial distribution. It extends the dynamic range over which precise statistical predictions can be made by the equivalent of performing a simulation with 50 times higher resolution, at no additional computational cost. We apply this technique to MW-mass halos, but it can easily be applied to halos of any mass. We find up to $20\%$ more substructures in MW-mass halos than found in previous studies. Our analysis lowers the mass of the MW halo required to accommodate the observation that the MW has only three satellites with a maximum circular velocity $V_{max}\ge 30km/s$ in the $\Lambda$CDM cosmology. The probability of having a subhalo population similar to that in the MW is $20\%$ for a virial mass, $M_{200}=1\times 10^{12}{M}_{\odot }$ and practically zero for halos more massive than $M_{200}=2\times 10^{12}{M}_{\odot }$.

17 pages, 14 figures, updated to match published version in MNRAS

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Cited by in corpus (14)

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• Constraints on the properties of warm dark matter using the satellite galaxies of the Milky Way
• Milky Way total Mass derived by Rotation Curve and Globular Cluster kinematics from Gaia EDR3
• A comparative study of satellite galaxies in Milky Way-like galaxies from HSC, DECaLS and SDSS
• ZOMG III: The effect of Halo Assembly on the Satellite Population
• The Origin of Lopsided Satellite Galaxy Distribution in Galaxy Pairs
• Local Group Analogs in $\Lambda$CDM cosmological simulations
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• Cosmological Zoom-In Simulations of Milky Way Host Mass Dark Matter Halos with a Blue-Tilted Primordial Power Spectrum
• Caught in the cosmic web: environmental effects on subhalo abundance and internal density profiles
• Game Theory in Cosmology
• Subhalo abundance and satellite spatial distribution in Milky Way-Andromeda-like paired haloes
• Dark Matter Energy Deposition and Production from the Table-Top to the Cosmos