Title:

Spatially Resolved Star Formation Histories of Local Group
Dwarf Spheroidal Galaxies.



Luca Rizzi
Institute for Astronomy
University of Hawaii




Abstract:


Large telescopes and the Hubble Space Telescope have
significantly improved our ability to study resolved stellar populations
in nearby galaxies. In most cases, the main sequence turn-off of the
oldest stellar components can now be observed. However, these observations
only concern a very small fraction of the galactic population,
particularly when the Milky Way satellites are considered.

Recent results obtained with the combined use of synthetic stellar
populations and wide field observations will be presented. Most of
data were collected with the Wide Field Imager at the ESO/MPG 2.2
meter telescope at La Silla, Chile, during my PhD.  Such data allow
tracing of age/metallicity gradients, detection of minor stellar
components, and the study of even the fastest stellar evolutionary
phases, such as blue-loop helium-burning phase and AGB bumps.  In most
cases, a spatially resolved star formation history was derived.