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 journalNature Astronomy, is set to shake up theories about the earliest formation of galactic structures and how they evolve.
Modelling shows big galaxies get bigger by merging with smaller ones
grow large by eating their smaller neighbours, new research reveals.
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
Sky survey provides clues to how they change over time.
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.
Researchers find evidence of a cataclysmic flare that punched so far out of the Galaxy its impact was felt 200,000 light years away.
titanic, expanding beam of energy sprang from close to the supermassive black
hole in the centre of the Milky Way just 3.5 million years ago, sending a
cone-shaped burst of radiation through both poles of the Galaxy and out into
the finding arising from research conducted by a team of scientists led by
Professor Joss Bland-Hawthorn from Australia’s ARC Centre of Excellence for All
Sky Astrophysics in 3 Dimensions (ASTRO 3D) and soon to be published in The
Researchers hunt for a 12-billion-year-old signal that marks the end of the post Big Bang “dark age”.
are closing in on a signal that has been travelling
across the Universe for 12 billion years, bringing them nearer to understanding
the life and death of the very earliest stars.
paper on the preprint site arXiv and
soon to be published in the Astrophysical Journal, a team led by Dr Nichole Barry from Australia’s University of Melbourne and
the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO
3D) reports a 10-fold improvement on data gathered by the Murchison Widefield
Array (MWA) – a collection of 4096 dipole antennas
set in the remote hinterland of Western Australia.