Star-forming compact groups (SFCGs): an ultraviolet search for a local sample

Autor(es)

Hernandez-Fernandez, Jonathan D. ^[1] ; Mendes de Oliveira, C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Astron, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 453, n. 2, p. 1965-1980, OCT 21 2015.
• Citações Web of Science: 1

Resumo

We present a local sample (z < 0.15) of 280 star-forming compact groups (SFCGs) of galaxies identified in the ultraviolet Galaxy Evolution EXplorer (GALEX) All-sky Imaging Survey (AIS). So far, just one prototypical example of SFCG, the Blue Infalling Group, has been studied in detail in the Local Universe. The sample of SFCGs is mainly the result of applying a Friends-of-Friends group finder in the space of celestial coordinates with a maximum linking-length of 1.5 arcmin and choosing groups with a minimum number of four members of bright UV-emitting 17< FUV< 20.5 sources (mostly galaxies) from the GALEX/AIS catalogue. The result from the search are 280 galaxy groups composed by 226, 39, 11 and 4 groups of four, five, six and seven bright ultraviolet (UV) members, respectively. Only 59 of these 280 newly identified SFCGs have a previous catalogued group counterpart. Group redshifts are available for at least one member in 75 per cent of the SFCGs, and over 40 per cent of the SFCGs have redshifts measured for two or more galaxies. 26 of the SFCGs appear to be located in the infalling regions of clusters with known redshift. The SFCG sample presents a combination of properties different from the group samples studied up to now, such as low-velocity dispersions (sigma(l-o-s) similar to 120 km s(-1)), small crossing-times (H(0)t(c) similar to 0.05) and high star formation content (95 per cent of star-forming galaxies). This points to the SFCGs being in an evolutionary stage distinct from those groups selected in the optical and near-infrared ranges. Once redshifts are obtained to discard interlopers, SFCGs will constitute a unique sample of SFCGs. (AU)

• Processo FAPESP: 12/13381-0 - Exploração do impacto dos processos ambientais em aglomerados e grupos de galáxias
• Beneficiário: Jonathan David Hernández Fernández
• Modalidade de apoio: Bolsas no Brasil - Pós-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