Major mergers going Notts: challenges for modern halo finders
Merging haloes with similar masses (i.e. major mergers) pose significant challenges for halo finders. We compare five halo-finding algorithms’ (ahf, hbt, rockstar, subfind, and velociraptor) recovery of halo properties for both isolated and cosmological major mergers. We find that halo positions and...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
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Oxford University Press
2015
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| Online Access: | https://eprints.nottingham.ac.uk/42484/ |
| _version_ | 1848796497054793728 |
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| author | Behroozi, Peter Knebe, Alexander Pearce, Frazer R. Elahi, Pascal Han, Jiaxin Lux, Hanni Mao, Yao-Yuan Muldrew, Stuart I. Potter, Doug Srisawat, Chaichalit |
| author_facet | Behroozi, Peter Knebe, Alexander Pearce, Frazer R. Elahi, Pascal Han, Jiaxin Lux, Hanni Mao, Yao-Yuan Muldrew, Stuart I. Potter, Doug Srisawat, Chaichalit |
| author_sort | Behroozi, Peter |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Merging haloes with similar masses (i.e. major mergers) pose significant challenges for halo finders. We compare five halo-finding algorithms’ (ahf, hbt, rockstar, subfind, and velociraptor) recovery of halo properties for both isolated and cosmological major mergers. We find that halo positions and velocities are often robust, but mass biases exist for every technique. The algorithms also show strong disagreement in the prevalence and duration of major mergers, especially at high redshifts (z > 1). This raises significant uncertainties for theoretical models that require major mergers for, e.g. galaxy morphology changes, size changes, or black hole growth, as well as for finding Bullet Cluster analogues. All finders not using temporal information also show host halo and subhalo relationship swaps over successive timesteps, requiring careful merger tree construction to avoid problematic mass accretion histories. We suggest that future algorithms should combine phase-space and temporal information to avoid the issues presented. |
| first_indexed | 2025-11-14T19:48:55Z |
| format | Article |
| id | nottingham-42484 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:48:55Z |
| publishDate | 2015 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-424842020-05-04T17:19:17Z https://eprints.nottingham.ac.uk/42484/ Major mergers going Notts: challenges for modern halo finders Behroozi, Peter Knebe, Alexander Pearce, Frazer R. Elahi, Pascal Han, Jiaxin Lux, Hanni Mao, Yao-Yuan Muldrew, Stuart I. Potter, Doug Srisawat, Chaichalit Merging haloes with similar masses (i.e. major mergers) pose significant challenges for halo finders. We compare five halo-finding algorithms’ (ahf, hbt, rockstar, subfind, and velociraptor) recovery of halo properties for both isolated and cosmological major mergers. We find that halo positions and velocities are often robust, but mass biases exist for every technique. The algorithms also show strong disagreement in the prevalence and duration of major mergers, especially at high redshifts (z > 1). This raises significant uncertainties for theoretical models that require major mergers for, e.g. galaxy morphology changes, size changes, or black hole growth, as well as for finding Bullet Cluster analogues. All finders not using temporal information also show host halo and subhalo relationship swaps over successive timesteps, requiring careful merger tree construction to avoid problematic mass accretion histories. We suggest that future algorithms should combine phase-space and temporal information to avoid the issues presented. Oxford University Press 2015-10-16 Article PeerReviewed Behroozi, Peter, Knebe, Alexander, Pearce, Frazer R., Elahi, Pascal, Han, Jiaxin, Lux, Hanni, Mao, Yao-Yuan, Muldrew, Stuart I., Potter, Doug and Srisawat, Chaichalit (2015) Major mergers going Notts: challenges for modern halo finders. Monthly Notices of the Royal Astronomical Society, 454 (3). pp. 3020-3029. ISSN 1365-2966 methods: numerical galaxies: haloes dark matter https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stv2046 doi:10.1093/mnras/stv2046 doi:10.1093/mnras/stv2046 |
| spellingShingle | methods: numerical galaxies: haloes dark matter Behroozi, Peter Knebe, Alexander Pearce, Frazer R. Elahi, Pascal Han, Jiaxin Lux, Hanni Mao, Yao-Yuan Muldrew, Stuart I. Potter, Doug Srisawat, Chaichalit Major mergers going Notts: challenges for modern halo finders |
| title | Major mergers going Notts: challenges for modern halo finders |
| title_full | Major mergers going Notts: challenges for modern halo finders |
| title_fullStr | Major mergers going Notts: challenges for modern halo finders |
| title_full_unstemmed | Major mergers going Notts: challenges for modern halo finders |
| title_short | Major mergers going Notts: challenges for modern halo finders |
| title_sort | major mergers going notts: challenges for modern halo finders |
| topic | methods: numerical galaxies: haloes dark matter |
| url | https://eprints.nottingham.ac.uk/42484/ https://eprints.nottingham.ac.uk/42484/ https://eprints.nottingham.ac.uk/42484/ |