| Full text | |
| Author(s): |
Laganá‚ TF
;
Lima Neto‚ GB
;
Andrade-Santos‚ F.
;
Cypriano‚ ES
Total Authors: 4
|
| Document type: | Journal article |
| Source: | Astronomy & Astrophysics; v. 485, n. 3, p. 633-644, 2008. |
| Abstract | |
Context. The luminous material in clusters of galaxies exists in two forms: the visible galaxies and the X-ray emitting intra-cluster medium. The hot intra-cluster gas is the major observed baryonic component of clusters, about six times more massive than the stellar component. The mass contained within visible galaxies is approximately 3% of the dynamical mass. Aims. Our aim was to analyze both baryonic components, combining X-ray and optical data of a sample of five galaxy clusters (Abell 496, 1689, 2050, 2631 and 2667), within the redshift range 0.03 < z < 0.3. We determined the contribution of stars in galaxies and the intra-cluster medium to the total baryon budget. Methods. We used public XMM-Newton data to determine the gas mass and to obtain the X-ray substructures. Using the optical counterparts from SDSS or CFHT we determined the stellar contribution. Results. We examine the relative contribution of galaxies, intra-cluster light and intra-cluster medium to baryon budget in clusters through the stellar-to-gas mass ratio, estimated with recent data. We find that the stellar-to-gas mass ratio within r(500) (the radius within which the mean cluster density exceeds the critical density by a factor of 500), is anti-correlated with the ICM temperature, which range from 24% to 6% while the temperature ranges from 4.0 to 8.3 keV. This indicates that less massive cold clusters are more prolific star forming environments than massive hot clusters. (AU) | |
| FAPESP's process: | 01/07342-7 - Evolution of galaxies in groups and in agglomerations |
| Grantee: | Claudia Lucia Mendes de Oliveira |
| Support Opportunities: | Research Projects - Thematic Grants |