Abstract
The shape of dark matter (DM) haloes plays a critical role in constraining cosmology with upcoming large-scale structure surveys. In this paper, we study the correlations between the triaxial shapes and formation histories in DM haloes in the MultiDark Planck 2 N-body cosmological simulation. We find that halo ellipticity is strongly correlated with halo properties that serve as proxies of halo formation history, such as halo concentration and the normalized peak-centroid offset. These correlations are nearly independent of the halo density peak height. We present a simple model for the correlation between halo ellipticity and concentration using conditional abundance matching, and provide fitting formulae for the multidimensional distributions of triaxial halo shape as a function of halo peak height. We apply our halo shape model to gauge the effects of halo ellipticity and orientation bias on the excess surface mass density profiles in cluster-sized haloes. Our model should be useful for exploring the impact of triaxial halo shape on cosmological constraints in upcoming weak lensing surveys of galaxy clusters.
Original language | English (US) |
---|---|
Pages (from-to) | 1029-1037 |
Number of pages | 9 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 500 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 2021 |
Keywords
- cosmology: Theory
- dark matter
- galaxies: clusters: general
- galaxies: groups: general
- large-scale structure of Universe
- methods: numerical
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science