New technique helps NASA’s James Webb Space Telescope
Astronomers have turned a cluster of galaxies into a gargantuan magnifying lens, using it to study another galaxy, 10.7 billion light years away, in unprecedented detail.
Massive galaxies with extra-large extended “puffy” disks produced stars for longer than their more compact cousins, new modelling reveals.
In a paper published in the Astrophysical Journal, researchers led by Dr Anshu Gupta and Associate Professor Kim-Vy Tran from Australia’s ARC Centre of Excellence in All Sky Astrophysics in 3 Dimensions (ASTRO 3D), show that the sheer size of a galaxy influences when it stops making new stars.
The complex mechanics determining how galaxies spin, grow, cluster and die have been revealed following the release of all the data gathered during a massive seven-year Australian-led astronomy research project.
The scientists observed 13 galaxies at a time, building to a total of 3068, using a custom-built instrument called the Sydney-AAO Multi-Object Integral-Field Spectrograph (SAMI), connected to the 4-metre Anglo-Australian Telescope (AAT) at Siding Spring Observatory in New South Wales. The telescope is operated by the Australian National University.
Theories on how the Milky Way formed are set to be rewritten following discoveries about the behaviour of some of its oldest stars.
An investigation into the orbits of the Galaxy’s metal-poor stars – assumed to be among the most ancient in existence – has found that some of them travel in previously unpredicted patterns.
How do stars destroy lithium? Was a drastic change in the shape of the Milky Way caused by the sudden arrival of millions of stellar stowaways?
These are just a couple of the astronomical questions likely to be answered following the release today of ‘GALAH DR3’, the largest set of stellar chemical data ever compiled.
The data, comprising more than 500 GB of information gleaned from more than 30 million individual measurements, was gathered by astronomers including Sven Buder, Sarah Martell and Sanjib Sharma from Australia’s ARC Centre of Excellence in All Sky Astrophysics in 3 Dimensions (ASTRO 3D) using the Anglo Australian Telescope (AAT) at the Australian Astronomical Observatory at Siding Spring in rural New South Wales.
Modelling shows big galaxies get bigger by merging with smaller ones
Distribution of dark matter density overlayed with the gas density. This image cleanly shows the gas channels connecting the central galaxy with its neighbours. Credit: Gupta et al/ASTRO 3D/ IllustrisTNG collaboration.
Galaxies
grow large by eating their smaller neighbours, new research reveals.
Exactly
how massive galaxies attain their size is poorly understood, not least because
they swell over billions of years. But now a combination of observation and
modelling from researchers led by Dr Anshu Gupta from Australia’s ARC Centre of
Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) has provided a
vital clue.
Lisa
Kewley has transformed our understanding of the early years of the Universe, the
development of galaxies, and what happens when they collide.
2020 James Craig Watson medal winner Professor Lisa Kewley in her office. Credit: ASTRO 3D
For her pioneering investigations across theory, modelling and observation, she will receive the US National Academy of Science’s biennial James Craig Watson Medal in Washington DC.
“At school I thought physics would be too hard. But I had a wonderful physics teacher whose
love for astronomy was contagious!” says Lisa.
Sky survey provides clues to how they change over time.
A simulation showing a section of the Universe at its broadest scale. A web of cosmic filaments forms a lattice of matter, enclosing vast voids. Credit: Tiamat simulation, Greg Poole
The direction in which a galaxy spins depends on its mass, researchers have found.
A team of astrophysicists analysed 1418 galaxies and found that small ones are likely to spin on a different axis to large ones. The rotation was measured in relation to each galaxy’s closest “cosmic filament” – the largest structures in the universe.
Filaments are massive thread-like formations, comprising huge amounts of matter – including galaxies, gas and, modelling implies, dark matter. They can be 500 million light years long but just 20 million light years wide. At their largest scale, the filaments divide the universe into a vast gravitationally linked lattice interspersed with enormous dark matter voids.