Gravitationally consistent halo catalogs and merger trees for precision cosmology

Peter S. Behroozi, Risa H. Wechsler, Hao Yi Wu, Michael T. Busha, Anatoly A. Klypin, Joel R. Primack

Research output: Contribution to journalArticlepeer-review

420 Scopus citations


We present a new algorithm for generating merger trees and halo catalogs which explicitly ensures consistency of halo properties (mass, position, and velocity) across time steps. Our algorithm has demonstrated the ability to improve both the completeness (through detecting and inserting otherwise missing halos) and purity (through detecting and removing spurious objects) of both merger trees and halo catalogs. In addition, our method is able to robustly measure the self-consistency of halo finders; it is the first to directly measure the uncertainties in halo positions, halo velocities, and the halo mass function for a given halo finder based on consistency between snapshots in cosmological simulations. We use this algorithm to generate merger trees for two large simulations (Bolshoi and Consuelo) and evaluate two halo finders (ROCKSTAR and BDM). We find that both the ROCKSTAR and BDM halo finders track halos extremely well; in both, the number of halos which do not have physically consistent progenitors is at the 1%-2% level across all halo masses. Our code is publicly available at Our trees and catalogs are publicly available at

Original languageEnglish (US)
Article number18
JournalAstrophysical Journal
Issue number1
StatePublished - Jan 20 2013
Externally publishedYes


  • dark matter
  • galaxies: abundances
  • galaxies: evolution
  • methods: numerical

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Gravitationally consistent halo catalogs and merger trees for precision cosmology'. Together they form a unique fingerprint.

Cite this