| Full text | |
| Author(s): |
Total Authors: 3
|
| Affiliation: | [1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Dept Astron, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 1
|
| Document type: | Journal article |
| Source: | Astronomy & Astrophysics; v. 511, FEB-MAR 2010. |
| Web of Science Citations: | 29 |
| Abstract | |
Context. X-ray data analysis have found that fairly complex structures at cluster centres are more common than expected. Many of these structures have similar morphologies, which exhibit spiral-like substructure. Aims. It is not yet well known how these structures are formed or maintained. Understanding the origin of these spiral-like features at the centre of some clusters is the major motivation behind this work. Methods. We analyse deep Chandra observations of 15 nearby galaxy clusters ( 0.01 < z < 0.06), and use X-ray temperature and substructure maps to detect small features at the cores of the clusters. Results. We detect spiral-like features at the centre of 7 clusters: A85, A426, A496, Hydra A cluster, Centaurus, Ophiuchus, and A4059. These patterns are similar to those found in numerical hydrodynamic simulations of cluster mergers with non-zero impact parameter. In some clusters of our sample, a strong radio source also occupies the inner region of the cluster, which indicates a possible connection between the two. Our investigation implies that these spiral-like structures may be caused by off-axis minor mergers. Since these features occur in regions of high density, they may confine radio emission from the central galaxy producing, in some cases, unusual radio morphology. (AU) | |
| FAPESP's process: | 08/05970-0 - Galaxy cluster collisions and their astrophysical consequences |
| Grantee: | Felipe Andrade Santos |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 06/56213-9 - New physics from space: formation and evolution of structures in the universe |
| Grantee: | Claudia Lucia Mendes de Oliveira |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 08/04318-7 - Intracluster gas enrichment and star formation efficiency in clusters of galaxies |
| Grantee: | Tatiana Ferraz Laganá |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |