scholarly journals The Central Dark Matter Fraction of Massive Early-Type Galaxies

2022 ◽  
Vol 8 ◽  
Author(s):  
C. Tortora ◽  
N. R. Napolitano
Keyword(s):  
Dark Matter ◽  
Total Mass ◽  
Mass Density ◽  
Mass Function ◽  
Initial Mass Function ◽  
Early Type ◽  
Galaxy Model ◽  
Stellar Initial Mass Function ◽  
Evolution With Time

Dark matter (DM) is predicted to be the dominant mass component in galaxies. In the central region of early-type galaxies it is expected to account for a large amount of the total mass, although the stellar mass should still represent the majority of the mass budget, depending on the stellar initial mass function (IMF). We discuss latest results on the DM fraction and mean DM density for local galaxies and explore their evolution with redshifts in the last 8 Gyr of the cosmic history. We compare these results with expectations from the ΛCDM model and discuss the role of the IMF and galaxy model through the central total mass density slope. We finally present future perspectives offered by next-generation instruments/surveys (Rubin/LSST, Euclid, CSST, WEAVE, 4MOST, and DESI), which will provide the unique chance to measure the DM evolution with time for an unprecedented number of galaxies and constrain their evolutionary scenario.

The IMF-SFH connection in massive early-type galaxies

2015 ◽  
Vol 11 (S315) ◽  
Author(s):  
I. Ferreras ◽  
C. Weidner ◽  
A. Vazdekis ◽  
F. La Barbera
Keyword(s):  
Age Distribution ◽  
Stellar Populations ◽  
Mass Function ◽  
Initial Mass Function ◽  
Population Synthesis ◽  
Early Type ◽  
Massive Galaxies ◽  
Stellar Initial Mass Function ◽  
The Many ◽  
The Imf

The stellar initial mass function (IMF) is one of the fundamental pillars in studies of stellar populations. It is the mass distribution of stars at birth, and it is traditionally assumed to be universal, adopting generic functions constrained by resolved (i.e. nearby) stellar populations (e.g., Salpeter 1955; Kroupa 2001; Chabrier 2003). However, for the vast majority of cases, stars are not resolved in galaxies. Therefore, the interpretation of the photo-spectroscopic observables is complicated by the many degeneracies present between the properties of the unresolved stellar populations, including IMF, age distribution, and chemical composition. The overall good match of the photometric and spectroscopic observations of galaxies with population synthesis models, adopting standard IMF choices, made this issue a relatively unimportant one for a number of years. However, improved models and observations have opened the door to constraints on the IMF in unresolved stellar populations via gravity-sensitive spectral features. At present, there is significant evidence of a non-universal IMF in early-type galaxies (ETGs), with a trend towards a dwarf-enriched distribution in the most massive systems (see, e.g., van Dokkum & Conroy 2010; Ferreras et al. 2013; La Barbera et al. 2013). Dynamical and strong-lensing constraints of the stellar M/L in similar systems give similar results, with heavier M/L in the most massive ETGs (see, e.g., Cappellari et al. 2012; Posacki et al. 2015). Although the interpretation of the results is still open to discussion (e.g., Smith 2014; La Barbera 2015), one should consider the consequences of such a bottom-heavy IMF in massive galaxies.

scholarly journals Radial variations in the stellar initial mass function of early-type galaxies

2014 ◽  
Vol 447 (2) ◽  
pp. 1033-1048 ◽  
Author(s):  
Ignacio Martín-Navarro ◽  
Francesco La Barbera ◽  
Alexandre Vazdekis ◽  
Jesús Falcón-Barroso ◽  
Ignacio Ferreras
Keyword(s):  
Mass Function ◽  
Initial Mass Function ◽  
Initial Mass ◽  
Early Type ◽  
Stellar Initial Mass Function

scholarly journals EVIDENCE FOR DARK MATTER CONTRACTION AND A SALPETER INITIAL MASS FUNCTION IN A MASSIVE EARLY-TYPE GALAXY

2012 ◽  
Vol 752 (2) ◽  
pp. 163 ◽  
Author(s):  
A. Sonnenfeld ◽  
T. Treu ◽  
R. Gavazzi ◽  
P. J. Marshall ◽  
M. W. Auger ◽  
...  
Keyword(s):  
Dark Matter ◽  
Mass Function ◽  
Initial Mass Function ◽  
Initial Mass ◽  
Early Type ◽  
Early Type Galaxy
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