Density profiles and substructure of dark matter halos: converging results at ultra-high numerical resolution
| dc.creator | Ghigna, Sebastiano | |
| dc.creator | Moore, Ben | |
| dc.creator | Governato, Fabio | |
| dc.creator | Lake, George | |
| dc.creator | Quinn, Tom | |
| dc.creator | Stadel, Joachim | |
| dc.date | 1999-10-08 | |
| dc.date | 2000-09-29 | |
| dc.date.accessioned | 2026-07-07T12:01:11Z | |
| dc.date.available | 2026-07-07T12:01:11Z | |
| dc.description | Can N-body simulations reliably determine the structural properties of dark matter halos? Focussing on a Virgo-sized galaxy cluster, we increase the resolution of current ``high resolution simulations'' by almost an order of magnitude to examine the convergence of the important physical quantities. We have 4 million particles within the cluster and force resolution 0.5 kpc/h (0.05% of the virial radius). The central density profile has a logarithmic slope of -1.5, as found in lower resolution studies of the same halo, indicating that the profile has converged to the ``physical'' limit down to scales of a few kpc. Also the abundance of substructure is consistent with that derived from lower resolution runs; on the scales explored, the mass and circular velocity functions are close to power laws of exponents ~ -1.9 and -4. Overmerging appears to be globally unimportant for suhalos with circular velocities > 100 km/s. We can trace most of the cluster progenitors from z=3 to the present; the central object (the dark matter analog of a cD galaxy)is assembled between z=3 and 1 from the merging of a dozen halos with v_circ \sim 300 km/s. The mean circular velocity of the subhalos decreases by ~ 20% over 5 billion years, due to tidal mass loss. The velocity dispersions of halos and dark matter globally agree within 10%, but the halos are spatially anti-biased, and, in the very central region of the cluster, they show positive velocity bias; however, this effect appears to depend on numerical resolution. | |
| dc.description | 19 pages, 13 figures, ApJ, in press. Text significantly clarified | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9910166 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9910166 | |
| dc.identifier | Astrophys.J.544:616,2000 | |
| dc.identifier | doi:10.1086/317221 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/207016 | |
| dc.subject | Astrophysics | |
| dc.title | Density profiles and substructure of dark matter halos: converging results at ultra-high numerical resolution | |
| dc.type | text |