General Overview of the DART Project
According to current structure
formation scenarios, dwarf galaxies are
the fundamental building blocks of galactic evolution. The
surviving systems thereby provide a
unique laboratory for detailed
study of the generic galactic assembly process and the
chemo-dynamical
evolution of the low-mass end of the galaxy distribution. FLAMES
provides us with
an unparalleled
opportunity to make ground-breaking detailed abundance
and kinematic
measurements for large numbers of stars in a sample of
Galactic dwarf
spheroidal systems (dSphs). This will
make possible for the first time: a detailed and complete determination
of
the combined star formation and
chemical enrichment histories of these systems; an accurate assessment
of their dynamical
state
and the role of dark matter in their development; the role of dSphs in
the assembly of
large
galactic systems; when and in which
type of environments dSphs first formed stars; how this
relates
to the re-ionization of the Universe; and how the diversity of the
star formation histories in
these systems arose.
We use FLAMES to make abundance and radial velocity
measurements of complete samples of red giant branch stars in the inner
regions of the dSphs, Sculptor, Fornax
and Sextans with pre-existing wide field imaging and to use the
2.2m/WFI for imaging the
outer
regions for lower resolution abundance and radial velocity FLAMES
measurements.
The programme began in August 2003, with two nights of
FLAMES
GTO time, and continued in September 2003 with two nights
of WFI time. Late in September were four
more nights of FLAMES visitor mode time. In Period 72 we have 8 hours
of WFI time
in service
mode and 66.5hours of FLAMES time, also in service mode.
This project is part ESO Large
Programme 171.B-0588 (PI: Tolstoy) entitled:
Dwarf galaxies:
remnants of
galaxy
formation and corner stones for understanding galaxy evolution
And part is Meudon GTO Programme
71.B-0641 (PI: Hill) entitled:
Star
formation history
of the
Sculptor dwarf spheroidal galaxy
The
Sample
The
Instrument
The
Team