Tag Archives: galaxy

Milky Way not unusual, astronomers find

Detailed cross-section of another galaxy reveals surprising similarities to our home

The first detailed cross-section of a galaxy broadly similar to the Milky Way, published today, reveals that our galaxy evolved gradually, instead of being the result of a violent mash-up. The finding throws the origin story of our home into doubt.

The galaxy, dubbed UGC 10738, turns out to have distinct ‘thick’ and ‘thin’ discs similar to those of the Milky Way. This suggests, contrary to previous theories, that such structures are not the result of a rare long-ago collision with a smaller galaxy. They appear to be the product of more peaceful change.

And that is a game-changer. It means that our spiral galaxy home isn’t the product of a freak accident. Instead, it is typical.

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Astronomers see ‘cosmic ring of fire’, 11 billion years ago

Unusual galaxy set to prompt rethink on how structures in the Universe form

Astronomers have captured an image of a super-rare type of galaxy – described as a “cosmic ring of fire” – as it existed 11 billion years ago.

The galaxy, which has roughly the mass of the Milky Way, is circular with a hole in the middle, rather like a titanic doughnut. Its discovery, announced in the journal Nature Astronomy, is set to shake up theories about the earliest formation of galactic structures and how they evolve.

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Hungry galaxies grow fat on the flesh of their neighbours

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.

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Mapping our galaxy’s magnetic field

Dr Charlotte Sobey, CSIRO and Curtin University

Astronomers from CSIRO and Curtin University have used pulsars to probe the Milky Way’s magnetic field. Working with colleagues in Europe, Canada, and South Africa, they have published the most precise catalogue of measurements towards mapping our Galaxy’s magnetic field in 3-D.

The Milky Way’s magnetic field is thousands of times weaker than Earth’s, but is of great significance for tracing the paths of cosmic rays, star formation, and many other astrophysical processes. However, our knowledge of the Milky Way’s 3-D structure is limited.

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Balloons over the Red Centre

A perfect view of the Milky Way

On a series of calm, cool mornings in April 2017, 70 French scientists (from the French space science agency CNES, CNRS IRAP, and the Université Paul Sabatier de Toulouse) launched three enormous balloons into the sky above the heart of Australia.

CNES was using the Alice Springs Balloon Launching Centre (ASBLS) to send three precision scientific instruments up to altitudes of 30–40 kilometres to make observations that are impossible from the ground.

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The Milky Way is warped

The first accurate 3D map of our galaxy reveals its true shape: warped and twisted.

Astronomers from Macquarie University and the Chinese Academy of Sciences have used 1339 ‘standard’ stars to map the real shape of our home galaxy in a paper published in Nature Astronomy today.

They found the Milky Way’s disc of stars becomes increasingly ‘warped’ and twisted the further away the stars are from the galaxy’s centre.

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Monster black holes supersize their galactic greed

Monster black holes lurking in the centres of galaxies are hungrier than previously thought, Melbourne scientists have discovered.

Artist’s impression of a star being pulled into a black hole. Credit: Gabriel Perez Diaz

Astrophysicist Alister Graham and his team at Swinburne University have revealed that these so-called supermassive black holes consume a greater portion of their galaxy’s mass the bigger the galaxy gets. The discovery overturns the longstanding belief that these supermassive black holes are always a constant 0.2 per cent of the mass of all the other stars in their galaxy.

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Academy recognition

Photo: Wouter Schellart’s geodynamics research into the activity of the Earth’s mantle, including the Mt Etna volcano, earned him the AAS Anton Hales medal for Earth Sciences. Credit: NASA

The Australian Academy of Science recognised five individuals for their career achievements in 2013.