The assembly process of massive ellipticals in colours: the test-case of NGC 1395

BOLAND, AGUSTIN; FAIFER, FAVIO R.; REYNALDI, VICTORIA; GUTIERREZ-SOTO, LUIS; ESCUDERO, CARLOS G.

Córdoba

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

Instituto de Astronomía Teórica y Experimental (IATE)

Massive elliptical galaxies (M > 10^11 MSun) 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; Forbes & Bridges, 2010). Studied by their color-index distributions, GC present a bimodal distribution in most of these galaxies (Faifer+2011). The color-indices, age, and metallicity of any stellar system are related in a strongly degenerated way (Worthey 1994). Being a good approximation to single stellar populations, GC (1) can be used to test whether such a bimodality in colors could be translated to intrinsic bimodality in metallicity, which in turn would be the result of two stellar populations of different origins; and (2) store recoverable information about the environmental conditions at the time and place of their formation. So the big questions are: what’s the true shape of the color distribution, and what property of the stellar population does it rely on? GC form in the most violent episodes of star formation that a galaxy might experience (Kruijssen 2019). Therefore, by answering this question we are probing into the star formation history, assembly and evolution of the galaxies that host them.