Dissecting galaxy triplets in the Sloan Digital Sky Survey Data Release 10: I. Stellar populations and emission line analysis

DUPLANCIC, FERNANDA; O'MILL, ANA LAURA; LAMBAS, D. G.; COSTA-DUARTE, MARCUS VINICIUS; SODRÉ, LAERTE

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 459 p. 2539 - 2549

0035-8711

We identify isolated galaxy triplets in a volume-limited sample from the SloanDigital Sky Survey Data Release 10. Our nal sample has 80 galaxy systems in theredshift range 0.046z60.1, brighter than Mr = 􀀀20:5 + 5 log h70. Spectral synthe-sis results and WHAN and BPT diagnostic diagrams were employed to classify thegalaxies in these systems as star-forming, active nuclei, or passive/retired.Our results suggest that the brightest galaxies drive the triplet evolution, as ev-idenced by the strong correlations between properties as mass assembly and meanstellar population age with triplet properties. Galaxies with intermediate luminosityor the faintest one within the triplet seem to play a secondary role. Moreover, therelation between age and stellar mass of galaxies is similar for these galaxies but dif-ferent for the brightest galaxy in the system. Most of the triplet galaxies are passiveor retired, according to the WHAN classication. Low mass triplets present dierentfractions of WHAN classes when compared to higher mass triplets. A census of WHANclass combinations shows the dominance of star-forming galaxies in low mass tripletswhile retired and passive galaxies prevail in high-mass systems. We argue that theseresults suggest that the local environment, through galaxy interactions driven by thebrightest galaxy, is playing a major role in triplet evolution.