Spin doctors: Astrophysicists find when galaxies rotate, size matters

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.

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Underwater grandmothers reveal big population of lethal sea snakes

A novel citizen science project in New Caledonia finds an ‘astonishing’ number of venomous reptiles in a popular swimming spot.

Fantastic grandmother Monique Mazière photographing sea snake number 79, nicknamed Déborah. Credit: Claire Goiran/UNC

A group of snorkelling grandmothers is helping scientists better understand marine ecology by photographing venomous sea snakes in waters off the city of Noumea, New Caledonia.

Two years ago the seven women, all in their 60s and 70s, who call themselves “the fantastic grandmothers”, offered to help scientists Dr Claire Goiran from the University of New Caledonia and Professor Rick Shine from Australia’s Macquarie University in their quest to document the sea snake population in a popular swimming spot known as Baie des citrons.

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Lonesome no more: white sharks hang with buddies

Apex marine predators choose who they hang with, researchers reveal.

A white shark (Carcharodon Carcharias). Credit: Wikimedia Commons

White sharks form communities, researchers have revealed.

Although normally solitary predators, white sharks (Carcharodon carcharias) gather in large numbers at certain times of year in order to feast on baby seals.

These groupings, scientists had assumed, were essentially random – the result of individual sharks all happening to turn up in the same area, attracted by abundant food.

Now, however, a group of researchers including behavioural ecologist Stephan Leu from Macquarie University in New South Wales, Australia, have used photo-identification and network analysis to show that many of the apex predators hang out in groups which persist for years.

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Not long ago, the centre of the Milky Way exploded

Researchers find evidence of a cataclysmic flare that punched so far out of the Galaxy its impact was felt 200,000 light years away.

An artist’s impression of the massive bursts of ionising radiation exploding from the centre of the Milky Way and impacting the Magellanic Stream.
Credit: James Josephides/ASTRO 3D

A 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 deep space.

That’s 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 Astrophysical Journal.

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It’s complicated: coral bleaching is caused by more than just heat

Analysis of reef damage in the Indo-Pacific during the 2016 El Nino reveals that several different stressors influence bleaching.

Coral responses to temperature depend on a range of local inputs. Image credit: Wikimedia Commons.

Scientists in the Indian and Pacific Oceans used the El Nino of 2016 – the warmest year on record – to evaluate the role of excess heat as the leading driver of coral bleaching and discovered the picture was more nuanced than existing models showed.

The findings were, in a word, complicated, according to marine researchers led by the US based Wildlife Conservation Society (WCS). The international cohort included scientists from Macquarie University in NSW, the University of Queensland, University of WA and two western Australian state government departments.

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Fast radio burst provides clues to galactic halo

Macquarie astronomers find a well of serenity in deep space.

Masters student Lachlan Marnoch has been credited as co-author in a paper in Science before even submitting his thesis. Credit Macquarie University

A massive galaxy four billion light-years from Earth is surrounded by a halo of tranquil gas.

The finding, which reveals a galactic halo much less dense and less magnetised than expected, was made by a team of astronomers that included two researchers from Macquarie University.

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Immune response depends on mathematics of narrow escapes

The shape of immune cells plays key role in recognising invaders.

The ruffled surface of a T cell means only very small areas make close contact with potential enemy cells. CREDIT: Blausen Medical

The way immune cells pick friends from foes can be described by a classic maths puzzle known as the “narrow escape problem”.

That’s a key finding arising from an international collaboration between biologists, immunologists and mathematicians, published in the journal Proceedings of the National Academy of Sciences.

The narrow escape problem is a framework often applied in cellular biology. It posits randomly moving particles trapped in a space with only a tiny exit, and calculates the average time required for each one to escape.

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There’s no place like home: butterflies stick to their burbs

Members of at least one species choose mates and egg sites based on where they were born, research reveals

Two American passionfruit butterflies, Heliconius charithonia, part of Dr Darrell Kemp’s research cohort.
Credit: Darrell Kemp.

Birthplace exerts a lifelong influence on butterflies as well as humans, new research reveals.

In a paper published in the journal Proceedings of the Royal Society B: Biological Sciences, Macquarie University ARC Future Fellow Associate Professor Darrell Kemp reveals that the American passionfruit butterfly, Heliconius charithonia, selects its mate and egg-laying site based on the species of plant that hosted its own egg.

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Pioneering collaboration between Indigenous communities and Macquarie wins Eureka Prize for STEM inclusion

The NISEP program has helped almost 1000 Indigenous school children enter leadership roles.

National Indigenous Science Education Program Eureka Prizes 2019 © Salty Dingo 2019 CRG-7382

The National Indigenous Science Education Program (NISEP), based at the Faculty of Science and Engineering at Sydney’s Macquarie University, won the inaugural the Eureka Prize for STEM Inclusion at the 2019 Australian Museum Eureka Prizes.

The awards were held in Sydney on Wednesday, August 28.

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