Diagnosing the merger remnant galaxy NGC 4382

FAIFER, F. R.; ESCUDERO, C. G.; SMITH CASTELLI, A. V.; SESTO, L. A.; REYNALDI, M. V.

Rosario

Congreso; 62 reunión Anual de la AAA; 2020

Universidad Nacional de Rosario

Current ideas for massive galaxy formation, in particular for early-type galaxies, focus on the concept of two-phase galaxy formation. Cosmological simulations indicate that large galaxies underwent an initial in-situ phase of formation followed by mass growth via an ex-situ (or accretion) phase. In these simulations, star formation can be tagged as occurring within the potential well/virial radius of the host primary galaxy (i.e. in-situ) or within the satellite galaxy that is eventually accreted (i.e. ex-situ). Thus in the simulations, in-situ and ex-situ formed material can be defined and tracked separately. However, from an observational point of view, it is very challenging to carry out detailed studies of stellar populations in the outer regions of galaxies beyond the Local Group, due to the faintness of the diffuse stellar light. In this preliminary work, we focus on the dynamically young galaxy NGC4382 using deep Gemini/GMOS photometry and spectroscopy in order to investigate its rich star formation history in the last Gyrs. NGC4382, classified by different authors as S0 or E2, would show interaction with its companion NGC4394. Besides, the galaxy presents peculiar features in its structure (e.g. shells, ripples), kinematics (e.g. kinematically decoupled core) and also in its globular cluster (GC) system (multiple GC subpopulations). All these characteristics make the galaxy an interesting case for studying the assembly of early-type galaxies in the local Universe.