On two mass estimators for clusters of galaxies
| dc.creator | Aceves, H. | |
| dc.creator | Perea, J. | |
| dc.date | 1999-02-11 | |
| dc.date.accessioned | 2026-07-07T02:30:25Z | |
| dc.date.available | 2026-07-07T02:30:25Z | |
| dc.description | The two most common mass estimators that use velocity dispersions and positions of objects in a stellar system, the virial mass estimator (VME) and the projected mass estimator (PME), are revisited and tested using N-body experiments. We consider here only spherical, isolated, and isotropic velocity dispersion systems. We have found that the PME can overestimate masses by ~ 20%, for realistic cluster mass profiles, if applied only to regions around the total system's "effective" radius. The VME can yield a correct mass at different radii provided that the total potential energy term is correctly taken into account and the system is completely sampled; otherwise, it may lead to similar errors as the PME. A surface pressure (3PV) term recently alluded to be usually neglected when using the VME and therefore required as a correction term is here found not necessarily required, although it can be used to yield a reasonable correction term. The preferred method here, however, is the virial theorem due to its simplicity and better agreement with N-body experiments. The possible reasons for the mass discrepancies found when using the PME and the VME in some N-body simulations are also briefly discussed. | |
| dc.description | 10 pages & 6 figures, uses epsf.sty. Accepted for publication in A&A | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9902166 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9902166 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/13808 | |
| dc.subject | Astrophysics | |
| dc.title | On two mass estimators for clusters of galaxies | |
| dc.type | text |