New images from the James Webb Space Telescope (JWST) have helped Australian astronomers unlock secrets of how infant galaxies started an explosion of star formation in the very early Universe.

Some early galaxies were abundant with a gas that glowed so bright it outshone emerging stars. In research published today, astronomers have now discovered just how prevalent these bright galaxies were some 12 billion years ago.

Images from the JWST have shown that almost 90% of the galaxies in the early universe had this glowing gas, producing so-called ‘extreme emission line features’.

Precise mapping of temperature variation gives clue to its evolution

A team of astronomers led by ASTRO 3D has drawn a temperature map of the dust drifting within one of the oldest spiral galaxies of the Universe which provides new insights into how fast the galaxy is growing. Until now researchers have only been able to measure the temperature of  most distant galaxies in broad terms, without showing how temperatures vary in individual areas.

This research, described in a paper published today in Monthly Notices of the Royal Astronomical Society (MNRAS) shows unambiguous temperature variation within the distant galaxy indicating two distinct heat sources – a supermassive black hole at the centre of the galaxy, and the heat generated by newly-formed stars in the surrounding rotating disk.

Download figure of galaxy as pdf.

New evidence for rapid heating in the early universe

Astrophysicists in Australia have shed new light on the state of the universe 13 billion years ago by measuring the density of carbon in the gases surrounding ancient galaxies.

The study adds another piece to the puzzle of the history of the universe.

“We found that the fraction of carbon in warm gas increased rapidly about 13 billion years ago, which may be linked to large-scale heating of gas associated with the phenomenon known as the ‘Epoch of Reionisation’,” says Dr Rebecca Davies, ASTRO 3D Postdoctoral Research Associate at Swinburne University of Technology, Australia and lead author of the paper describing the discovery.

The alignment between galaxy spins and the large-scale structure of the universe reveals the processes by which different components of galaxies form.

Like our own Milky Way, most galaxies have two components: an extended disk in which new stars form from gas and a central bulge of mostly older stars that grows over time.

An observational study recently published in Monthly Notices of the Royal Astronomical Society found that the size of the galaxies’ bulge changes how their spins align with the surrounding structure.

Thousands more potential lenses await assessment

Earlier this year a machine learning algorithm identified up to 5,000 potential gravitational lenses that could transform our ability to chart the evolution of galaxies since the Big Bang.

Now astronomer Kim-Vy Tran from ASTRO 3D and UNSW Sydney and colleagues have assessed 77 of the lenses using the Keck Observatory in Hawai’i and Very Large Telescope in Chile. She and her international team confirmed that 68 out of the 77 are strong gravitational lenses spanning vast cosmic distances.

Aussie astronomers react to NASA Webb first images.

Media contacts: Niall Byrne, niall@scienceinpublic.com.au, or
Jane Watkins, jane@scienceinpublic.com.au,

Nearly 40 researchers across Australia are eagerly awaiting data from Webb for their projects. Many of them are available to talk on Tuesday about what they hope to see with Webb and about their reaction to the first pictures

What will Australians see with Webb?

Aussie astronomers available for interviews in Melbourne, Sydney, Brisbane, Perth and Canberra.

They’re using Webb to look for the first stars, the first galaxies, baby planets, massive black holes.

Media contacts: Niall Byrne, niall@scienceinpublic.com.au, 0417-131-977 or
Jane Watkins, jane@scienceinpublic.com.au, 0425 803 204

Over the past 30 years, Hubble has transformed science and culture, revealing a Universe of 200 billion galaxies. Webb will see further, solving today’s mysteries and creating new ones.

On Tuesday morning Joe Biden will release ‘the first picture’ then NASA will release a suite of images early Wednesday morning from the James Webb Space Telescope, the successor to Hubble.

Nearly 40 researchers across Australia are eagerly awaiting data from web for their projects. Many of them are available to talk on Tuesday about what they hope to see with Webb and about their reaction to the first pictures.

Much of the Webb data is flowing back to Earth through Tidbinbilla, and some comes from an instrument designed by Peter Tuthill at the University of Sydney. He is relieved and excited. “This is a day I have been looking forward to for a big part of my career. Everything about the Webb is so over-the-top audacious – from the titanic articulated mirror down to its orbit out in the cold voids of interplanetary space.”

Our galaxy is a giant ‘smoothie’ of blended stars and gas but a new study tells us where the components came from

Images and media kit download

In its early days, the Milky Way was like a giant smoothie, as if galaxies consisting of billions of stars, and an enormous amount of gas had been thrown together into a gigantic blender. But a new study picks apart this mixture by analysing individual stars to identify which originated inside the galaxy and which began life outside.

Stars evolve according to the elements they manufacture

Stars are giant factories that produce most of the elements in the Universe – including the elements in us, and in the Earth’s metal deposits. But what stars produce changes over time.

Two new papers published in MNRAS shed light on how the youngest generation of stars will eventually stop contributing metals back to the universe.

The authors are all members of ASTRO 3D, the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions. They are based at Monash University, the Australian National University (ANU), and the Space Telescope Science Institute.