Séminaire/Seminar Galaxies |
| « Cosmic gas accretion from filaments onto galaxy clusters using the IllustrisTNG simulation » |
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Jade Pasté |
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Galaxy clusters grow through matter accretion from the cosmic web, primarily along filaments. In this talk, I will present a study of gas accretion onto galaxy clusters using 415 clusters from the IllustrisTNG-300 hydrodynamical simulation at z=0 (Pasté et al, 2026). By comparing isotropic and anisotropic radial profiles of thermodynamic properties and gas velocities, we investigate how filaments shape the accretion process.
We identify two distinct accretion regimes. In the cluster environment, warm gas transported by filaments enters the warm-hot circumcluster medium while remaining colder than the surrounding gas, producing transverse temperature gradients. Closer to the cluster outskirts, filamentary gas penetrates the hot intracluster medium, accompanied by strong tangential velocity gradients. We also show that cluster mass and dynamical state strongly influence these features, with relaxed and massive systems displaying stronger temperature discontinuities. Finally, our results support a picture of anisotropic accretion with virial shocks mainly located near the filament–cluster interface. |
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jeudi 22 octobre 2026 - 11:00 Salle Entresol Daniel Chalonge Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |