Research Note

Theoretical color–magnitude diagrams and the star forming histories of interacting open multi-population model galaxies: bursts and busts

¹ Dipartimento di Fisica “Enrico Fermi”, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
² INFN – Sezione di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy e-mail: shore@df.unipi.it

Received: 4 April 2005
Accepted: 13 June 2005

Abstract

This note presents theoretical color-magnitude diagrams (CMDs) and metallicity evolution for Galactic multipopulation models coupled to stellar evolution models for systems undergoing stripping and re-accretion of ambient material, called “open” systems in our recent studies (Valle et al. 2005, A&A, 435, 551). We show that the observables for such systems, in particular those related to the recovered star formation as a function of time, are ambiguous – systems with non-monotonic star formation rates can appear as either bursting systems or galaxies with a hiatus in the star formation.