Hubble Deep Field South
AAO telescopes assist Hubble
the Christmas and New Year of 1995/1996, the Hubble Space Telescope spent
hundreds of hours examining a small patch of northern sky. The Hubble Deep
Field (HDF), as it became known, provided the 'deepest' ever image of the
Universe, and provides astronomers with valuable information about the
formation of galaxies out to distances of 10 billion light years.
In October this year, the HST
again spent hundreds of hours looking at a small patch of sky but this
time in the south, called the Hubble Deep Field South (HDF-S). The picture
shows a section of the HDF-S. To see the whole HDF-S, click on the picture
(courtesy of R. Williams (STScI), the HDF-S Team and NASA).
The two Anglo-Australian Observatory
telescopes, the Anglo-Australian Telescope (AAT) and the UK Schmidt
Telescope (UKST) helped the Hubble Space Telescope find thousands of new
galaxies. The telescopes were used to help choose the patch of sky in which
the HST found the previously unknown galaxies.
The Field contains a distant
quasar at the centre of the field. The quasar was used to light-up material
lying between the Earth and quasar, yielding new information on otherwise
invisible material lying many thousands of millions of light years from
the Earth. This material may be associated with the formation of star systems
such as our own galaxy, and may reveal some of the early history of the
Finding a suitable patch of sky
was not easy. Areas to look at are very limited, due to the constraints
of the HST orbit and the need to avoid pointing at the Sun and the Earth.
Other limitations include avoiding bright stars and not being obscured
by our own Galaxy. In fact, there are only about half a dozen suitable
A patch of sky in the constellation
of Tucana containing a likely quasar was identified by analysing a photographic
plate taken over ten years ago with the UKST. The quasar was confirmed
with the 2-degree field instrument on the AAT. The quasar is over 10 thousand
million light years from Earth its relatively bright optical magnitude
has led to it being the choice for the HDF-S.