The concentration-velocity dispersion relation in galaxy groups
| dc.creator | Faltenbacher, Andreas | |
| dc.creator | Mathews, William G. | |
| dc.date | 2006-08-29 | |
| dc.date | 2007-06-08 | |
| dc.date.accessioned | 2026-07-07T10:23:30Z | |
| dc.date.available | 2026-07-07T10:23:30Z | |
| dc.description | Based on results from cold dark matter N-body simulations we develop a dynamical model for the evolution of subhaloes within host haloes of galaxy groups. Only subhaloes more massive than 5 times 10^8 M_{sol} at the time of accretion are examined because they are massive enough to possibly host luminous galaxies. As they orbit within a growing host potential the subhaloes are subject to tidal stripping and dynamical friction. We consider groups of equal mass (M_{vir} = 3.9 times 10^{13} M_{sol}) at redshift z=0 but with different concentrations associated with different formation times. We investigate the variation of subhaloe (or satellite galaxy) velocity dispersion with host concentration and/or formation time. In agreement with the Jeans equation the velocity dispersion of subhaloes increases with the host concentration. Between concentrations ~5 and ~20 the subhaloe velocity dispersions increase by ~25 per cent. By applying a simplified tidal disruption criterion, i.e. rejection of all subhaloes with a tidal truncation radius below 3 kpc at z=0, the central velocity dispersion of 'surviving' subhaloes increases substantially for all concentrations. The enhanced central velocity dispersion among surviving subhaloes is caused by a lack of slow tangential motions. Additionally, we present a fitting formula for the velocity anisotropy parameter β(r) which does not depend on concentration if the group-centric distances are scaled by r_s, the characteristic radius of the NFW-profile. | |
| dc.description | 12 pages, 11 figures, published in MNRAS | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0608610 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0608610 | |
| dc.identifier | Mon.Not.Roy.Astron.Soc.375:313-323,2007 | |
| dc.identifier | doi:10.1111/j.1365-2966.2006.11295.x | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/175852 | |
| dc.subject | Astrophysics | |
| dc.title | The concentration-velocity dispersion relation in galaxy groups | |
| dc.type | text |