Star Formation Depends On Gas Location, Not Quantity: Study

A new Australian study has revealed that it's not the amount of gas in a galaxy, but where that gas is located, that determines whether new stars form.

The Western Australia-based International Center for Radio Astronomy Research (ICRAR) said in a release on Wednesday that using the powerful Australian Square Kilometer Array Pathfinder (ASKAP) radio telescope, astronomers studied gas in around 1,000 galaxies as part of the WALLABY survey.

Previous surveys were limited to mapping gas in only a few hundred galaxies, but the WALLABY survey has mapped the atomic hydrogen gas in a significantly larger sample of galaxies, the release said.

The key ingredient in star formation is atomic hydrogen gas. The team discovered that galaxies forming stars tend to have gas concentrated in the same regions where stars are being born, according to an ICRAR study published in Publications of the Astronomical Society of Australia.

Thanks to high-resolution observations from telescopes like ASKAP, operated by the Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia's national science agency, at the CSIRO Murchison Radio-astronomy Observatory in Western Australia, researchers were able to pinpoint the location and density of atomic gas in more galaxies than ever before, the release said.

Lead author Seona Lee, a PhD student at the University of Western Australia's ICRAR node, said the findings offer fresh insight into how gas gives rise to new stars. "It was very exciting to see a correlation between star formation and where the atomic hydrogen gas is located."

ICRAR's professor Barbara Catinella, who co-leads the WALLABY survey, explained that location matters, which is like baking a cake. "While different cakes require different amounts of flour, to bake a cake properly, you focus on the flour that's in the bowl, not the unused flour left in the package."

The findings suggest that future studies into galaxy growth should focus not just on how much gas is present, but where it's concentrated.

The ICRAR is an equal joint venture between Curtin University and the University of Western Australia, with funding support from the state government.
-XINHUA