Astronomy and Astrophysics, volume 507, 723-746 (2009/11-4)
Star formation in the intragroup medium and other diagnostics of the evolutionary stages of compact groups of galaxies.
TORRES-FLORES S., MENDES DE OLIVEIRA C., DE MELLO D.F., AMRAM P., PLANA H., EPINAT B. and IGLESIAS-PARAMO J.
Abstract (from CDS):
Compact groups of galaxies are entities that have high densities of galaxies and serve as laboratories to study galaxy interactions, intergalactic star formation and galaxy evolution. The main goal of this study is to search for young objects in the intragroup medium of seven compact groups of galaxies: HCG 2, 7, 22, 23, 92, 100 and NGC 92 as well as to evaluate the stage of interaction of each group. We used Fabry-Perot velocity fields and rotation curves together with GALEX NUV and FUV images and optical R-band and HI maps. (i) HCG 7 and HCG 23 are in early stages of interaction; (ii) HCG 2 and HCG 22 are mildly interacting; and (iii) HCG 92, HCG 100 and NGC 92 are in late stages of evolution. We find that all three evolved groups contain populations of young blue objects in the intragroup medium, consistent with ages <100Myr, of which several are younger than <10Myr. We also report the discovery of a tidal dwarf galaxy candidate in the tail of NGC 92. These three groups, besides containing galaxies that have peculiar velocity fields, also show extended HI tails. Our results indicate that the advanced stage of evolution of a group, together with the presence of intragroup HI clouds, may lead to star formation in the intragroup medium. A table containing all intergalactic HII regions and tidal dwarf galaxies confirmed to date is appended.
galaxies: evolution - galaxies: interactions - galaxies: intergalactic medium - galaxies: kinematics and dynamics
Tables 3-8: [TMD2009] HCG NNN NN N=86. Table 9: [TMD2009] NGC 92 N (Nos 1-5).
In reflist, MENDES DE OLIVEIRA 2004, ApJ, L17 is MENDES DE OLIVEIRA 2004ApJ...605L..17M.
View the references in ADS
To bookmark this query, right click on this link: simbad:2009A&A...507..723T and select 'bookmark this link' or equivalent in the popup menu