IALP 13078
INSTITUTO DE ASTROFISICA LA PLATA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Downsizing Quemoarqueológico en galaxias elípticas: Impacto de una TH-IGIMF
Autor/es:
GARGIULO, IGNACIO D.; CORA, SOFÍA A.; PADILLA, NELSON D.
Lugar:
Córdoba
Reunión:
Conferencia; Reunión Friends of Friends; 2014
Institución organizadora:
Instituto de Astronomía Teórica y Experimental
Resumen:
We make use of a semi-analytical model of galaxy formation to investigate the origin
of the observed correlation between [alpha/Fe] abundance ratios and stellar mass in elliptical
galaxies.We implement a new galaxy-wide stellar initial mass function (Top Heavy Integrated
Galaxy Initial Mass Function, TH-IGIMF) in the semi-analytic model SAG and evaluate its
impact on the chemical evolution of galaxies. Massive
galaxies reach higher [alpha/Fe] abundance ratios because they are characterized by more topheavy
IMFs as a result of their higher SFR. As a consequence of our analysis, the value of
the minimum embedded star cluster mass, which is a free parameter involved in the THIGIMF
theory, is found to be as low as 5M⊙. We find that, regardless of
galaxy mass, older galaxies (with formation redshifts > 2) are formed in shorter time-scales
(< 2Gyr), thus achieving larger [alpha /Fe] values. Hence, the time-scale of galaxy formation
alone cannot explain the slope of the [alpha /Fe]-galaxy mass relation, but is responsible for the
big dispersion of [alpha/Fe] abundance ratios at fixed stellar mass.
