Brightest group galaxies and the large-scale environment

LUPARELLO, H.; LARES, M.; PAZ, D.; YARYURA, C. YAMILA; GARCÍA LAMBAS, D.; PADILLA, NELSON

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 448 p. 1483 - 1493

0035-8711

We study the population of galaxies in groups and the dependence of their statistical properties on the surrounding large?scale environment, using SDSS-DR7 data. Galaxies are ranked according to luminosity within each group and classified morphologically by the Sérsic index. We have considered two different samples taking into account if the host groups reside in superstructures or elsewhere. We find a significant dependence of the properties of late?type brightest group galaxies on the large?scale environment. The other member galaxies exhibit only the influence of the group they inhabit. Late?type brightest galaxies show statistically significant higher luminosities and stellar masses, redder u-r colours, lower star formation activity and larger star?formation time?scale when embedded in superstructures. By contrast, the properties of the early?type brightest group galaxy are remarkably similar regardless of the group global environment. Our analysis comprises tests against the dependence on the host group luminosity and we argue that group brightest member properties are not only deter- mined by the host halo, but also by the large?scale structure which can influence the accretion process onto their late?type brightest galaxies.