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Achieving convergence in galaxy formation models by augmenting N-body merger trees

Benson, Andrew J. and Cannella, Chris and Cole, Shaun (2016) Achieving convergence in galaxy formation models by augmenting N-body merger trees. Computational Astrophysics and Cosmology, 3 (1). Art. No. 3. ISSN 2197-7909. doi:10.1186/s40668-016-0016-3.

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Accurate modeling of galaxy formation in a hierarchical, cold dark matter universe requires the use of sufficiently high-resolution merger trees to obtain convergence in the predicted properties of galaxies. When semi-analytic galaxy formation models are applied to cosmological N-body simulation merger trees, it is often the case that those trees have insufficient resolution to give converged galaxy properties. We demonstrate a method to augment the resolution of N-body merger trees by grafting in branches of Monte Carlo merger trees with higher resolution, but which are consistent with the pre-existing branches in the N-body tree. We show that this approach leads to converged galaxy properties.

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Benson, Andrew J.0000-0001-5501-6008
Additional Information:© 2016 Benson et al. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Received: 7 April 2016; Accepted: 17 August 2016; Published: 22 August 2016. The Millennium Simulation databases used in this paper and the web application providing online access to them were constructed as part of the activities of the German Astrophysical Virtual Observatory (GAVO). SC acknowledges support by the Science and Technology Facilities Council [ST/L00075X/1]. AJB acknowledges valuable discussion with Yu Lu. We acknowledge the support of the Ahmanson Foundation through the provision of computational resources used in this work. Authors’ contributions: AJB assisted in development of the implementation of the algorithm within Galacticus, performed the Millennium simulation tests, and wrote the majority of the text. CC developed the code to implement the augmenting algorithm within the Galacticus code, carried out tests of convergence of the algorithm, and contributed to the text of the paper. SC originated the idea of our algorithm, and contributed to the text of the paper. The authors declare that they have no competing interests.
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Science and Technology Facilities Council (STFC)ST/L00075X/1
Ahmanson FoundationUNSPECIFIED
Issue or Number:1
Record Number:CaltechAUTHORS:20161109-110227671
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Official Citation:Achieving convergence in galaxy formation models by augmenting N-body merger trees Andrew J Benson, Chris Cannella and Shaun Cole Computational Astrophysics and CosmologySimulations, Data Analysis and Algorithms 2016 3:3 DOI: 10.1186/s40668-016-0016-3
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:71884
Deposited By: Tony Diaz
Deposited On:09 Nov 2016 20:19
Last Modified:11 Nov 2021 04:52

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