Revisiting the Age-Metallicity Relationship of the Fornax spheroidal dwarf galaxy

A.E. PIATTI; A. DEL PINO; A APARICIO; S. HIDALGO

Bol. Asociación Argentina de Astronomía

BAAA

Año: 2013 vol. 56 p. 45 - 48

1669-9521

              We present results about the Age-Metallicity Relationship(AMR) of three fields located in the central region of the spheroidal dwarfgalaxy of Fornax, from the birth of the galaxy until ∼ 1 Gyr ago, inde-pendent of any other previous approach. The resulting AMRs describethe trend of the representative stellar populations in each field, namely,the dominant populations in terms of stellar density. Our results suggestthat the innermost regions of Fornax does not contain very old stars (age> 12 Gyr), whereas the studied outer fields do not account for star fieldpopulations younger than ∼ 3 Gyr. On the other side, the AMRs of twofields show possible metallicity bimodality during the first half ofthe galaxy lifetime. However, more recent star formation processes (age∼ 1-2 Gyr) result in a intrinsic metallicity dispersion smaller than forrelatively older generations of stars.