The gbpTrees algorithm for building merger trees
Overview
gbpTrees is a halo merger-tree algorithm designed to minimize cascading inconsistencies that arise from halo-finder errors or ambiguities. It matches radially sorted particle ID lists forward and backward in time across multiple snapshots to correct pathological cases and produce robust progenitor links.
Why it matters: reducing merger-tree pathologies improves derived merger rates and halo growth histories across cosmic time.
- Designed to suppress cascading merger-tree errors from halo-finder ambiguities.
- Uses radially sorted particle IDs with forward and backward time matching.
- Available in gbpCode with full details in the code paper.
Key Results
Concise summaries of flagship gbpTrees results, with details in the papers below.
- Convergence-tested merger trees across configuration-space halo finders.
- Merger rates for friends-of-friends halos and substructures across cosmic time.
- Robust recovery of progenitor lines despite ambiguous halo-finder outputs.
The following provides links to publications describing gbpTrees and movies highlighting the fiducial system used in the convergence study.
Selected Publications
Peer-reviewed work that introduces the algorithm and its applications.
Selected Movies
Animations of the fiducial system used in the gbpTrees convergence study.
This study presents the gbpTrees algorithm and uses it to condect a detailed convergence study of merger tree construction with a configuration space halo finder. Merger rates for friends-of-friends halos and substructures across nearly all observed galactic history are presented.
Click here to see the full paper on NASA ADS (if you do not have access to the journal, follow the arXiv link).