Phase-Space Evolution of Dark Matter Halos
| dc.creator | Peirani, S. | |
| dc.creator | Pacheco, J. A. de Freitas | |
| dc.date | 2007-01-10 | |
| dc.date | 2009-05-03 | |
| dc.date.accessioned | 2026-07-07T13:10:48Z | |
| dc.date.available | 2026-07-07T13:10:48Z | |
| dc.description | (Context) In a Universe dominated by dark matter, halos are continuously accreting mass (violently or not) and such mechanism affects their dynamical state. (Aims) The evolution of dark matter halos in phase-space, and using the phase-space density indicator Q=rho/sigma^3 as a tracer, is discussed. (Methods) We have performed cosmological N-body simulations from which we have carried a detailed study of the evolution of ~35 dark halos in the interval 0<z<10. (Results)The follow up of individual halos indicates two distinct evolutionary phases. First, an early and fast decrease of Q associated to virialization after the gravitational collapse takes place. The nice agreement between simulated data and theoretical expectations based on the spherical collapse model support such a conjecture. The late and long period where a slow decrease of the phase-space density occurs is related to accretion and merger episodes. The study of some merger events in the phase-space (radial velocity versus radial distance) reveals the formation of structures quite similar to caustics generated in secondary infall models of halo formation. After mixing in phase-space, halos in quasi-equilibrium have flat-topped velocity distributions (negative kurtosis) with respect to Gaussians. The effect is more noticiable for captured satellites and/or substructures than for the host halo. | |
| dc.description | submitted to A&A | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0701292 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0701292 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/229102 | |
| dc.subject | Astrophysics | |
| dc.title | Phase-Space Evolution of Dark Matter Halos | |
| dc.type | text |