Young Globular Clusters in NGC 1316

FAIFER, F.; FORTE, J. C.; SESTO, L.; ESCUDERO, C.; SMITH CASTELLI, A.

La Serena

Congreso; Second Binational Meeting AAA-Sochias; 2018

AAA - Sochias

We present multi-object spectroscopy of the inner zone of the globular cluster (GC) system associated to the intermediate-age merger remnant NGC 1316. Using the multi-object mode of the GMOS camera, we obtained spectra for 40 GCs candidates. Our kinematics results, in conjunction with spectroscopic data published by other authors, strongly reinforce the existence of an orderly movement in the inner zone of the GC system ofNGC 1316. In a second stage, we determined ages, metallicities and α-element abundances for each GC present in the sample, through the measurement of different Lick/IDS indices and their comparison with simple stellar population models. We confirmed the existence of multiple GC populations associated with NGC 1316, where the presence of a dominant subpopulation of very young GCs, with an average age of 2.1 Gyr, Metallicities between -0.5 < [Z/H] < 0.5 dex and α-element abundances in the range -0.2 < [α/Fe] < 0.3 dex, stands out. Several objects in our sample present subsolar values of [α/Fe] and a large spread of [Z/H] and ages. Some of these objects could actually be stripped nuclei, possibly accreted during minor merger events. Finally, the results have been analyzed with the aim of describing the different episodes of star formation and thus design a more complete picture about the evolutionary history of the galaxy. We conclude that these pieces of evidence could be indicating that this galaxy has cannibalized one or more gas-rich Galaxies, where the last fusion event occurred about 2 Gyr ago.