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| Main Authors: | , , , , |
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| Format: | Preprint |
| Published: |
2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2504.04575 |
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| _version_ | 1866912312884985856 |
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| author | Abdullah, Mohamed H. Mabrouk, Raouf H. Ishiyama, Tomoaki Wilson, Gillian Amin, Magdy Y. |
| author_facet | Abdullah, Mohamed H. Mabrouk, Raouf H. Ishiyama, Tomoaki Wilson, Gillian Amin, Magdy Y. |
| contents | Galaxy clusters are powerful laboratories for studying both cosmic structure formation and galaxy evolution. We present a comprehensive analysis of the velocity anisotropy profile, beta(r), in galaxy clusters using the Uchuu-UniverseMachine mock galaxy catalog, which combines the large-volume Uchuu N-body simulation with the UniverseMachine galaxy formation model. Focusing on clusters with log(M200) >= 13.9 [h^-1 M_sun] up to redshift z = 1.5, we investigate the behavior of beta(r) as a function of cluster-centric radius, mass, and redshift. We find that beta(r) exhibits a universal shape: it rises from isotropic values near the cluster core, peaks at approximately 1.7 R200, declines around 3.4 R200 due to orbital mixing, and increases again in the outskirts due to the dominance of first-infalling galaxies. Our results show that more massive clusters have higher radial anisotropy and larger peak beta values. Moreover, beta(r) evolves with redshift, with high-redshift clusters displaying more radially dominated orbits and enhanced infall motions. We further derive redshift-dependent power-law scaling relations between M200 and key physical radii: hydrostatic (R_hs), infall (R_inf), and turnaround (R_ta). These findings offer a robust theoretical framework for interpreting the dynamical properties of observed galaxy clusters and provide key insights into the evolution of their dynamical state over cosmic time. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2504_04575 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Quantifying the Velocity Anisotropy Profile of Galaxy Clusters Using the Uchuu Cosmological Simulation Abdullah, Mohamed H. Mabrouk, Raouf H. Ishiyama, Tomoaki Wilson, Gillian Amin, Magdy Y. Cosmology and Nongalactic Astrophysics Galaxy clusters are powerful laboratories for studying both cosmic structure formation and galaxy evolution. We present a comprehensive analysis of the velocity anisotropy profile, beta(r), in galaxy clusters using the Uchuu-UniverseMachine mock galaxy catalog, which combines the large-volume Uchuu N-body simulation with the UniverseMachine galaxy formation model. Focusing on clusters with log(M200) >= 13.9 [h^-1 M_sun] up to redshift z = 1.5, we investigate the behavior of beta(r) as a function of cluster-centric radius, mass, and redshift. We find that beta(r) exhibits a universal shape: it rises from isotropic values near the cluster core, peaks at approximately 1.7 R200, declines around 3.4 R200 due to orbital mixing, and increases again in the outskirts due to the dominance of first-infalling galaxies. Our results show that more massive clusters have higher radial anisotropy and larger peak beta values. Moreover, beta(r) evolves with redshift, with high-redshift clusters displaying more radially dominated orbits and enhanced infall motions. We further derive redshift-dependent power-law scaling relations between M200 and key physical radii: hydrostatic (R_hs), infall (R_inf), and turnaround (R_ta). These findings offer a robust theoretical framework for interpreting the dynamical properties of observed galaxy clusters and provide key insights into the evolution of their dynamical state over cosmic time. |
| title | Quantifying the Velocity Anisotropy Profile of Galaxy Clusters Using the Uchuu Cosmological Simulation |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2504.04575 |