The past and the present of NGC 1316 through Gemini + GMOS

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

San Francisco

Congreso; Science and Evolution of Gemini Observatory 2018; 2018

Observatorio Internacional Gemini

We present here the results obtained from a photometric and spectroscopic study of the CG system of the early type galaxy NGC 1316 (Fornax A), based on observations obtained with Gemini + GMOS. The photometric properties of this system and of the galaxy are analyzed, confirming the presence of different subpopulations of CGs, in which a remarkable subpopulation of bright and intermediate colors objects stands out. Our data is analyzed in conjunction with Vr data published by other authors. In particular, ages and metalities of a sample of 35 CGs confirmed by deep GMOS spectroscopy are presented, finding that this sample is dominated by a set of young metal rich CGs. These results are compared with other data, also obtained with GMOS, belonging to other early-type galaxies which show no evidence of recent star formation. The data set is analyzed and an attempt is made to give clues about the past of NGC 1316. We conclude that these pieces of evidence could indicate that this galaxy has cannibalized one or more gas-rich galaxies, where the last fusion event took place around 2 Gyr ago.