Context. Dwarf irregular galaxies are relatively simple unevolved
objects where it is easy to test models of galactic chemical
evolution.
Aims. We attempt to determine the star formation and gas
accretion history of IC 10, a local dwarf irregular for which
abundance, gas, and mass determinations are available.
Methods. We apply
detailed chemical evolution models to predict the evolution of
several chemical elements (He, O, N, S) and compared our predictions
with the observational data. We consider additional constraints such
as the present-time gas fraction, the star formation rate (SFR), and
the total estimated mass of IC 10. We assume a dark matter halo for
this galaxy and study the development of a galactic wind. We
consider different star formation regimes: bursting and continuous.
We explore different wind situations: i) normal wind, where
all the gas is lost at the same rate and ii) metal-enhanced
wind, where metals produced by supernovae are preferentially lost.
We study a case without wind. We vary the star formation efficiency
(SFE), the wind efficiency, and the time scale of the gas infall,
which are the most important parameters in our models.
Results. We find that
only models with metal-enhanced galactic winds can reproduce the
properties of IC 10. The star formation must have proceeded in bursts
rather than continuously and the bursts must have been less numerous
than ~10 over the whole galactic lifetime. Finally, IC 10 must
have formed by a slow process of gas accretion with a timescale of
the order of 8 Gyr
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