the U N I V E R S E T O D A YSpace Exploration News From Around the Internet, Updated Every Weekday.
May 19th, 2000 - Issue #239
5 May 2000
The astronomers have been using Australia's largest optical telescope, the 3.9-m Anglo-Australian Telescope and a remarkable instrument called 2dF to gather the information. The 2dF instrument allows astronomers to observe and analyse 400 objects at once, and on a long clear night, they can log the positions of more than 2000 galaxies.
The Australian team leader, Dr Matthew Colless from the ANU said, "It has taken less than two years to measure the distances for these 100,000 galaxies. Without the 2dF instrument, this project would have taken decades. We are now well on our way to reaching our target of 250,000 galaxies by the end of 2001. Our map of the Universe will then be ten times larger than that produced by any previous survey."
The computer visualisation has also broken new ground. It is the first time that actual data have been used to create a simulation like this. Professor Matthew Bailes from Swinburne University's Centre for Astrophysics and Supercomputing said "Most of us are used to the Hollywood versions of travelling through the Universe but this version is much closer to the truth. We have used the information from the survey and combined it with actual photographs of galaxies, many taken using the Anglo-Australian Telescope.
Professor Brian Boyle, the Director of the Anglo-Australian Observatory said, "Astronomers will use our three-dimensional map to learn about the nature of the Universe for many years to come, but it has always been part of our aim to provide a version so that the general public can pilot their own intergalactic spaceship. Eventually we will distribute it for educational use."
Although it has only taken less than two years to gather this huge amount of data, it is really the culmination of more than seven years of effort. The 2dF instrument, one of the most complex pieces of astronomical equipment ever built, is the key to the survey. It uses 400 optical fibres, all of which can be positioned by an incredibly accurate robotic arm in an hour. The optical fibres pipe the light from each galaxy into one of two spectrographs. The spectrographs split the light into its component colours and after analysis astronomers can tell how far away a galaxy is.
* The project, the 2dF Galaxy Redshift Survey is a large international collaboration involving more than 30 scientists from 11 institutions. In Australia, the Anglo-Australian Observatory, the Australian National University and the University of NSW are involved. The survey aims to learn more about the structure of the Universe, how galaxies are made and how they form into larger structures. It will also allow astronomers to accurately measure the total amount of matter in the Universe and get more of an idea of the nature of 'dark matter' that makes up at least 90% of the total mass of the Universe.
Some images are available at ftp://ftp.aao.gov.au/pub/local/rb/
The movie can be viewed at http://www.swin.edu.au/astronomy/2dfmovie/