Spiral-like structure at the centre of nearby clusters of galaxies

Autor(es)

Lagana, T. F. ^[1] ; Andrade-Santos, F. ^[1] ; Lima Neto, G. B. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Dept Astron, BR-05508900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Astronomy & Astrophysics; v. 511, FEB-MAR 2010.
• Citações Web of Science: 29

Resumo

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)

• Processo FAPESP: 08/05970-0 - Colisões de aglomerados de galáxias e suas consequências astrofísicas
• Beneficiário: Felipe Andrade Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 06/56213-9 - Nova física no espaço: formação e evolução de estruturas no universo
• Beneficiário: Claudia Lucia Mendes de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 08/04318-7 - Enriquecimento do gás intra-aglomerado e a eficiência de formação estelar em aglomerados de galáxias
• Beneficiário: Tatiana Ferraz Laganá
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado