Segregation effects according to the evolutionary stage of galaxy groups

Autor(es)

Ribeiro, A. L. B. ^[1] ; Lopes, P. A. A. ^[2] ; Trevisan, M. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estadual Santa Cruz, Lab Astrofis Teor & Observac, BR-45650000 Ilheus, BA - Brazil

^[2] Univ Fed Rio de Janeiro, Observ Valongo, BR-21941 Rio De Janeiro - Brazil

^[3] Univ Sao Paulo, Inst Astron & Geofis, BR-09500900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 409, n. 1, p. L124-L127, NOV 2010.
• Citações Web of Science: 16

Resumo

We study segregation phenomena in 57 groups selected from the 2dF Percolation-Inferred Galaxy Groups (2PIGG) catalogue of galaxy groups. The sample corresponds to those systems located in areas of at least 80 per cent redshift coverage out to 10 times the radius of the groups. The dynamical state of the galaxy systems was determined after studying their velocity distributions. We have used the Anderson-Darling test to distinguish relaxed and non-relaxed systems. This analysis indicates that 84 per cent of groups have galaxy velocities consistent with the normal distribution, while 16 per cent of them have more complex underlying distributions. Properties of the member galaxies are investigated taking into account this classification. Our results indicate that galaxies in Gaussian groups are significantly more evolved than galaxies in non-relaxed systems out to distances of similar to 4R(200), presenting significantly redder (B - R) colours. We also find evidence that galaxies with M(R) <= -21.5 in Gaussian groups are closer to the condition of energy equipartition. (AU)

• Processo FAPESP: 08/50198-3 - Elementos alfa em populações estelares compostas
• Beneficiário: Marina Trevisan
• Modalidade de apoio: Bolsas no Brasil - Doutorado