The mass of a halo
Abstract
We discuss the different definitions of the mass of a halo in common use and how one may convert between them. Using N-body simulations we show that mass estimates based on spherical averages are much more tightly correlated with each other than with masses based on the number of particles in a halo. The mass functions pertaining to some different mass definitions are estimated and compared to the ``universal form'' of Jenkins et al. (\cite{JFWCCEY}). Using a different simulation pipeline and a different cosmological model we show that the mass function is well fit by the Jenkins et al. (\cite{JFWCCEY}) fitting function, strengthening the claim to universality made by those authors. We show that care must be taken to match the definitions of mass when using large N-body simulations to bootstrap scaling relations from smaller hydrodynamical runs to avoid observationally significant bias in the predictions for abundances of objects.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- February 2001
- DOI:
- 10.1051/0004-6361:20000357
- arXiv:
- arXiv:astro-ph/0011495
- Bibcode:
- 2001A&A...367...27W
- Keywords:
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- METHODS: N-BODY SIMULATIONS;
- Astrophysics
- E-Print:
- 6 pages,to appear in A&