Probing baryonic processes and gastrophysics in the formation of the
  Milky Way dwarf satellites: I. metallicity distribution properties
  In this paper, we study the chemical properties of the stars in the dwarf
satellites around the MW-like host galaxies, and explore the possible effects
of several baryonic processes, including supernova (SN) feedback, the
reionization of the universe and H$_2$ cooling, on them and how current and
future observations may put some constraints on these processes. We use a
semi-analytical model to generate MW-like galaxies, for which a fiducial model
can reproduce the luminosity function and the stellar metallicity--stellar mass
correlation of the MW dwarfs. Using the simulated MW-like galaxies, we focus on
investigating three metallicity properties of their dwarfs: the stellar
metallicity--stellar mass correlation of the dwarf population, and the
metal-poor and metal-rich tails of the stellar metallicity distribution in
individual dwarfs. We find that (1) the slope of the stellar
metallicity--stellar mass correlation is sensitive to the SN feedback strength
and the reionization epoch; (2) the extension of the metal-rich tails is mainly
sensitive to the SN feedback strength; (3) the extension of the metal-poor
tails is mainly sensitive to the reionization epoch; (4) none of the three
chemical properties are sensitive to the H$_2$ cooling process; and (5)
comparison of our model results with the current observational slope of the
stellar metallicity--stellar mass relation suggests that the local universe is
reionized earlier than the cosmic average and local sources may have a
significant contribution to the reionization in the local region, and an
intermediate to strong SN feedback strength is preferred. Future observations
of metal-rich and metal-poor tails of stellar metallicity distributions will
put further constraints on the SN feedback and the reionization processes.
