HST/ACS Ultra Deep Field
The HST/ACS Ultra Deep Field
is a survey carried out using the
Advanced Camera for Surveys
on HST and taking advantage of 412 orbits of the
Director's Discretionary time . The survey is
expected to reach up to 1.5 mag deeper than the Hubble Deep Field
(HDF) and provide the deepest optical view of the Universe.
The data will be made public.
Scientific drivers of the UDF include probing the
tail of the reionization epoch, constraining the star formation history
of the Universe, probing the faint end of the galaxy luminosity function,
and tracking the origin, structure, and merger history of galaxies as
they evolve onto and off the Hubble sequence.
The final structure of the UDF Survey represents a consensus recommendation
of a Scientific Advisory Committee to STScI Director Steven Beckwith,
presented by the
Local Working Group.
The UDF will consist of a single ultra-deep field (412 orbits in total)
within the CDF-S GOODS area, observed with the ACS Wide Field Camera using
four filters: F435W (56 orbits), F606W(56 orbits), F775W (150 orbits),
and F850LP (150 orbits). The HST/ACS UDF is expected to reach a 10 sigma
limiting AB magnitudes (for extended source and a 0.2 sq arcsec or 9x9 pix
aperture) which is deeper than the Hubble Deep Field (HDF) by ~1 magnitude
in the F435W (B) and F606W (V) filters and ~1.5 magnitude deeper in
For more details see the
WWW home page (last update Nov. 1, 2003)