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

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

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  Sloan Digital Sky Survey Data Release 10. Our final sample has 80  galaxysystems in the redshift range 0.04 ≤ z ≤ 0.1, brighter thanMr = -20.5 + 5 log h70. Spectral synthesis resultsand WHAN and BPT  diagnostic diagrams were employed to classify thegalaxies in these  systems as star-forming, active nuclei, orpassive/retired. Our results suggest that the brightest galaxies drivethe triplet evolution, as evidenced by the strong correlations betweenproperties as mass  assembly and mean stellar population age with tripletproperties. Galaxies with intermediate luminosity or the faintest onewithin the  triplet seem to play a secondary role. Moreover, the relationbetween age and stellar mass of galaxies is similar for these galaxiesbut  different for the brightest galaxy in the system. Most of thetriplet galaxies are passive or retired, according to the WHANclassification.  Low-mass triplets present different fractions of WHANclasses when  compared to higher mass triplets. A census of WHAN class combinations shows the dominance of star-forming galaxies in low-masstriplets while retired and passive galaxies prevail in high-masssystems. We argue that these results suggest that the local  environment,through galaxy interactions driven by the brightest  galaxy, is playing amajor role in triplet evolution.