Revisiting the classics: is [Mg/Fe] a good proxy for galaxy formation time-scales?

Martín-Navarro, I.
Referencia bibliográfica

Monthly Notices of the Royal Astronomical Society: Letters, Volume 456, Issue 1, p.L104-L108

Fecha de publicación:
2
2016
Número de autores
1
Número de autores del IAC
1
Número de citas
26
Número de citas referidas
26
Descripción
In the local Universe, massive early-type galaxies exhibit enhanced [Mg/Fe] ratios, which has been traditionally interpreted as the result of a rapid (τ ≲ 1 Gyr) collapse. However, recent claims of a non-universal, steep initial mass function call for a revision of this standard interpretation. In the present work we show how the simultaneous consideration of a high [Mg/Fe] and a steep IMF slope would imply unreasonably short (τ ˜ 7 Myr) and intense (SFR ˜105 M⊙ yr-1) formation events for massive early-type galaxies. We discuss possible caveats and explanations to this apparent inconsistency, and we suggest that further IMF determinations, both in the local Universe and at high redshift, are necessary to better understand the problem.