Australian National University | University of Sydney | 2018 Apr 23
A new international study involving The Australian National University (ANU) and The University of Sydney has found that galaxies grow bigger and puffier as they age.
Co-researcher Professor Matthew Colless from ANU said that stars in a young galaxy moved in an orderly way around the galaxy’s disk, much like cars around a racetrack.
Telescope in Hawaii. (Credit: NAOJ, Caroline Foster, and Dan Taranu)
“All galaxies look like squashed spheres, but as they grow older they become puffier with stars going around in all directions,” said Professor Colless... “Our Milky Way is more than 13 billion years old, so it is not young anymore, but the galaxy still has both a central bulge of old stars and spiral arms of young stars.”
To work out a galaxy’s shape, the research team measured the movement of stars with an instrument called SAMI on the Anglo-Australian Telescope at the ANU Siding Spring Observatory.
They studied 843 galaxies of all kinds and with a hundred-fold range in mass. ...
A Relation Between the Characteristic Stellar Ages of Galaxies and Their Intrinsic Shapes - Jesse van de Sande et al
- Nature Astronomy (online 23 Apr 2018) DOI: 10.1038/s41550-018-0436-x
arXiv.org > astro-ph > arXiv:1804.07769 > 20 Apr 2018
