News_

Astronomers spun up by galaxy-shape finding

September 12, 2017
Game-changing Australian instrument nets huge haul of galaxies
Scientists have measured how a galaxy’s spin affects its shape – and found faster-spinning galaxies are flatter and rounder. The discovery was made sampling 845 galaxies and could help provide insights into a galaxy’s past.

For the first time astronomers have measured how a galaxy’s spin affects its shape.

It sounds simple, but measuring a galaxy’s true 3D shape is a tricky problem that astronomers first tried to solve 90 years ago.

“This is the first time we’ve been able to reliably measure how a galaxy’s shape depends on any of its other properties – in this case, its rotation speed,” said research team leader Dr Caroline Foster of the University of Sydney’s School of Physics, who completed this research while working at the Australian Astronomical Observatory.

The study was published on 11 September in the journal Monthly Notices of the Royal Astronomical Society.

Galaxies can be shaped like a pancake, a sea urchin or a football, or anything in between.

Faster-spinning galaxies are flatter than their slower-spinning siblings, the team found.

“And among spiral galaxies, which have disks of stars, the faster-spinning ones have more circular disks,” said team member Professor Scott Croom of the University of Sydney.

The team made its findings with SAMI (the Sydney-AAO Multi-object Integral field unit), an instrument jointly developed by The University of Sydney and the Australian Astronomical Observatory with funding from CAASTRO, the ARC Centre of Excellence for All-sky Astrophysics.

SAMI gives detailed information about the movement of gas and stars inside galaxies. It can examine 13 galaxies at a time and so collect data on huge numbers of them.

Dr Foster’s team used a sample of 845 galaxies, over three times more than the biggest previous study. This large number was the key to solving the shape problem.

Because a galaxy’s shape is the result of past events such as merging with other galaxies, knowing its shape also tells us about the galaxy’s history.

The ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) is a collaboration between The University of Sydney, The Australian National University, The University of Melbourne, Swinburne University of Technology, The University of Queensland, The University of Western Australia and Curtin University, the last two participating together as the International Centre for Radio Astronomy Research (ICRAR). CAASTRO is funded under the Australian Research Council (ARC) Centre of Excellence program, with additional funding from the seven participating universities and from the NSW State Government’s Science Leveraging Fund.

Share

  • News_

    • December 11, 2017
      Preparing your journey to The University of Sydney

      Choosing to be an international student is one of the most important decisions of your life, each year the University of Sydney welcomes 1,000s of international students from across 200 countries to their Sydney Campus. The University of Sydney community is an exciting, vibrant and a diverse mix of students, researchers and academics and we...

    • December 11, 2017
      Centre in China hosts Austrade education team

      The University of Sydney Centre in China hosted Rhett Miller, Trade Commissioner (Education) of Australian Trade and Investment Commission, and Consul (Commercial) of Australian Consulate-General Commercial Section, and his team on 8 December, 2017. The team from Austrade’s education section had their annual planning meeting at the Centre in China after finishing the 2017 Austrade...

Related articles

  • August 31, 2017
    Eureka Award for University of Sydney robotics expert

    University of Sydney engineer Professor Salah Sukkarieh has won the 2017 CSIRO Eureka Prize for Leadership in Innovation and Science, presented at a gala dinner on 30 August in the Sydney Town Hall. Presented annually by the Australian Museum, the prestigious Eureka Prizes reward excellence in the fields of scientific research and innovation, science leadership, school science and science...

  • August 8, 2017
    Membrane technology engineer recognised for innovation

    Dr Qianhong She from the Faculty of Engineering and Information Technologies was recently named a recipient of the 2017 North American Membrane Society (NAMS) Young Membrane Scientist Award. The prestigious award is given to early career researchers in recognition of their academic achievements, as well as their outstanding potential to become future leaders in the...

  • July 5, 2017
    University of Sydney engineer named one of Australia’s most innovative

    Professor Yi from the faculty’s School of Electrical and Information Engineering was one of three Australian engineers recognised in the ‘Manufacturing and Automation’ category for her new pain-free, low-cost method to help people with diabetes monitor their ketone levels. She will continue to develop this project as one of the first cohort of fellows of...