Sussing merger trees: stability and convergence

Wang, Yang and Pearce, Frazer R. and Knebe, Alexander and Schneider, Aurel and Srisawat, Chaichalit and Tweed, Dylan and Jung, Intae and Han, Jiaxin and Helly, John and Onions, Julian and Elahi, Pascal J. and Thomas, Peter A. and Behroozi, Peter and Yi, Sukyoung K. and Rodriguez-Gomez, Vicente and Mao, Yao-Yuan and Jing, Yipeng and Lin, Weipeng (2016) Sussing merger trees: stability and convergence. Monthly Notices of the Royal Astronomical Society, 459 (2). pp. 1554-1568. ISSN 1365-2966

[img]
Preview
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (5MB) | Preview

Abstract

Merger trees are routinely used to follow the growth and merging history of dark matter haloes and subhaloes in simulations of cosmic structure formation. Srisawat et al. compared a wide range of merger-tree-building codes. Here we test the influence of output strategies and mass resolution on tree-building. We find that, somewhat surprisingly, building the tree from more snapshots does not generally produce more complete trees; instead, it tends to shorten them. Significant improvements are seen for patching schemes that attempt to bridge over occasional dropouts in the underlying halo catalogues or schemes that combine the halo-finding and tree-building steps seamlessly. The adopted output strategy does not affect the average number of branches (bushiness) of the resultant merger trees. However, mass resolution has an influence on both main branch length and the bushiness. As the resolution increases, a halo with the same mass can be traced back further in time and will encounter more small progenitors during its evolutionary history. Given these results, we recommend that, for simulations intended as precursors for galaxy formation models where of the order of 100 or more snapshots are analysed, the tree-building routine should be integrated with the halo finder, or at the very least be able to patch over multiple adjacent snapshots.

Item Type: Article
Keywords: methods: numerical, galaxies: haloes– galaxies: evolution, dark matter
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Physics and Astronomy
Identification Number: 10.1093/mnras/stw726
Depositing User: Eprints, Support
Date Deposited: 03 May 2017 14:59
Last Modified: 04 May 2017 14:43
URI: http://eprints.nottingham.ac.uk/id/eprint/42481

Actions (Archive Staff Only)

Edit View Edit View