Title
Building Halo Merger Trees from the Q Continuum Simulation
Abstract
Cosmological N-body simulations rank among the most computationally intensive efforts today. A key challenge is the analysis of structure, substructure, and the merger history for many billions of compact particle clusters, called halos. Effectively representing the merging history of halos is essential for many galaxy formation models used to generate synthetic sky catalogs, an important application of modern cosmological simulations. Generating realistic mock catalogs requires computing the halo formation history from simulations with large volumes and billions of halos over many time steps, taking hundreds of terabytes of analysis data. We present fast parallel algorithms for producing halo merger trees and tracking halo substructure from a single-level, density-based clustering algorithm. Merger trees are created from analyzing the halo-particle membership function in adjacent snapshots, and substructure is identified by tracking the "cores" of merging halos – sets of particles near the halo center. Core tracking is performed after creating merger trees and uses the relationships found during tree construction to associate substructures with hosts. The algorithms are implemented with MPI and evaluated on a Cray XK7 supercomputer using up to 16,384 processes on data from HACC, a modern cosmological simulation framework. We present results for creating merger trees from 101 analysis snapshots taken from the Q Continuum, a large volume, high mass resolution, cosmological simulation evolving half a trillion particles.
Year
DOI
Venue
2017
10.1109/HiPC.2017.00052
2017 IEEE 24th International Conference on High Performance Computing (HiPC)
Keywords
Field
DocType
merger trees,dark matter halos,cosmological Nbody simulations
Cluster (physics),Supercomputer,Parallel algorithm,Computer science,Parallel computing,Sky,Galaxy formation and evolution,Computational science,Halo,Cluster analysis,Substructure
Conference
ISSN
ISBN
Citations 
1094-7256
978-1-5386-2294-0
0
PageRank 
References 
Authors
0.34
1
7
Name
Order
Citations
PageRank
Esteban Rangel162.40
Nicholas Frontiere2614.13
Salman Habib39815.24
Katrin Heitmann414414.49
Wei-keng Liao5109587.98
Ankit Agrawal633.17
Alok Choudhary732231.06