The assembly process of massive ellipticals in colours: optical/IR photometry of NGC 1395

AGUSTÍN BOLAND; FAVIO FAIFER; VICTORIA REYNALDI; LUIS A. GUTIÉRREZ SOTO; CARLOS ESCUDERO

Córdoba

Conferencia; 4th Regional Extragalactic Astronomy Meeting: 60 Years Of The Sersic Law; 2023

Instituto de Astronomía Teórica y Experimental (IATE)

Massive elliptical galaxies are known to host ancient and metal-rich stellar populations, and also are found in the densest regions of the Universe. Those stellar populations are considered equivalent to fossil records of the star formation history and the chemical evolution of the ISM during the early stages of the Universe. This early epoch was also the time of the formation of globular clusters (GC). Being a good approximation to single stellar populations, it is believed that they store recoverable information about the environmental conditions at the time and place of their formation. In such a context, the existence of distinct subpopulations of GC holds clues to the star formation history, assembly and evolution of the galaxies that host them.This poster presents the analysis of the assembly process of the massive early-type galaxy NGC 1395. To do so, we have combined optical and near-infrared GC photometry obtained with the Gemini-South telescope. Different subpopulations of GC candidates are identified in several colour planes. Special emphasis is placed on the combination of different photometric bands in an attempt to minimise the effects that horizontal branch stars may have on the age-metallicity degeneracy. The spatial distribution of the identified subgroups is also studied. These results are analysed in the context of the two-phase formation scenario of massive elliptical galaxies.