Non-Gaussian velocity distributions - the effect on virial mass estimates 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-20080090 Rio De Janeiro - Brazil

^[3] Inst Astron & Geofis USP, BR-05508090 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 413, n. 1, p. L81-L85, MAY 2011.
• Citações Web of Science: 15

Resumo

We present a study of nine galaxy groups with evidence for non-Gaussianity in their velocity distributions out to 4R(200). This sample is taken from the 57 groups selected from the 2dF Percolation-Inferred Galaxy Groups (2PIGG) catalogue of galaxy groups. Statistical analysis indicates that the non-Gaussian groups have masses significantly higher than that of the Gaussian groups. We also have found that all non-Gaussian systems seem to be composed of multiple velocity modes. Besides, our results indicate that multimodal groups should be considered as a set of individual units with their own properties. In particular, we have found that the mass distributions of such units are similar to that of the Gaussian groups. Our results reinforce the idea of non-Gaussian systems as complex structures in the phase space, likely corresponding to secondary infall aggregations at a stage before virialization. The understanding of these objects is relevant for cosmological studies using groups and clusters through the mass function evolution. (AU)

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