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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Fossil groups in the Millennium Simulation Evolution of the brightest galaxies

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Autor(es):
Diaz-Gimenez, E. [1, 2] ; Muriel, H. [1, 2] ; de Oliveira, C. Mendes [3]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] IATE CONICET UNC, RA-5000 Cordoba - Argentina
[2] OAC UNC, RA-5000 Cordoba - Argentina
[3] Univ Sao Paulo, IAG, BR-09500900 Sao Paulo - Brazil
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: Astronomy & Astrophysics; v. 490, n. 3, p. 965-973, NOV 2008.
Citações Web of Science: 35
Resumo

Aims. We create a catalogue of simulated fossil groups and study their properties, in particular the merging histories of their first-ranked galaxies. We compare the simulated fossil group properties with those of both simulated non-fossil and observed fossil groups. Methods. Using simulations and a mock galaxy catalogue, we searched for massive (>5 x 10(13) h(-1) M-circle dot) fossil groups in the Millennium Simulation Galaxy Catalogue. In addition, we attempted to identify observed fossil groups in the Sloan Digital Sky Survey Data Release 6 using identical selection criteria. Results. Our predictions on the basis of the simulation data are: (a) fossil groups comprise about 5.5% of the total population of groups/clusters with masses larger than 5 x 10(13) h(-1) M-circle dot. This fraction is consistent with the fraction of fossil groups identified in the SDSS, after all observational biases have been taken into account; (b) about 88% of the dominant central objects in fossil groups are elliptical galaxies that have a median R-band absolute magnitude of similar to-23.5-5 log h, which is typical of the observed fossil groups known in the literature; (c) first-ranked galaxies of systems with M > 5 x 10(13) h(-1) M-circle dot, regardless of whether they are either fossil or non-fossil, are mainly formed by gas-poor mergers; (d) although fossil groups, in general, assembled most of their virial masses at higher redshifts in comparison with non-fossil groups, first-ranked galaxies in fossil groups merged later, i.e. at lower redshifts, compared with their non-fossil-group counterparts. Conclusions. We therefore expect to observe a number of luminous galaxies in the centres of fossil groups that show signs of a recent major merger. (AU)

Processo FAPESP: 01/07342-7 - Evolução de galáxias em grupos e em aglomerados
Beneficiário:Claudia Lucia Mendes de Oliveira
Linha de fomento: Auxílio à Pesquisa - Temático