THE 3.9 METRE ANGLO-AUSTRALIAN TELESCOPE IS COLLECTING OPTICAL GALAXY DATA FOR THE GAMA SURVEY. CREDIT: BARNABY NORRIS.
A new ‘super survey’ is producing the largest database of galaxy measurements, spanning the last five billion years of cosmic history. The International Galaxy and Mass Assembly (GAMA) project is combining data from ground-and space-based observatories to measure the ‘haloes’ of dark matter that surround galaxies.
“The Cold Dark Matter (CDM) model of cosmology makes predictions about how galaxies cluster and, in many cases, collide and merge,” says Andrew Hopkins, a GAMA team member. “Our measurements of the speeds of galaxies will reveal the distribution of dark matter, and enable us to test the CDM model.”
PHOTO: DARK MATTER DOMINATES GALAXIES AND GROUPS OF GALAXIES, YET ITS IDENTITY REMAINS UNKNOWN. CREDIT: DAVID MALIN, AUSTRALIAN ASTRONOMICAL OBSERVATORY.
Australian astronomers have long been contributing to our understanding of a strange cosmological phenomenon—the Universe’s missing matter.
In the early 1970s, Ken Freeman of the Australian National University (ANU) determined that spiral galaxies must contain more matter than we can see. He postulated that dark matter—an invisible material first proposed 40 years earlier—must make up at least half the mass of these galaxies. Now, patches of dark matter are thought to be scattered across the Universe, playing a major role in holding galaxies and groups of galaxies together. Continue reading Spinning galaxies reveal missing matter→
Each year we identify early-career scientists with a discovery and bring them to Melbourne for a communication boot camp. Here are some of their stories.
Jacek Jasieniak sprinkling quantum dots. Credit: Jacek Jasieniak
Imagine printing your own room lighting, lasers, or solar cells from inks you buy at the local newsagent. Jacek Jasieniak and colleagues at CSIRO, the University of Melbourne and the University of Padua in Italy, have developed liquid inks based on quantum dots that can be used to print such devices and in the first demonstration of their technology have produced tiny lasers. Quantum dots are made of semiconductor material grown as nanometre-sized crystals, around a millionth of a millimetre in diameter. The laser colour they produce can be selectively tuned by varying their size.
Colin Scholes operates a test rig for his carbon capture membrane. Credit: CO2 CRC
High tech cling wraps that ‘sieve out’ carbon dioxide from waste gases can help save the world, says Melbourne University chemical engineer, Colin Scholes who developed the technology. The membranes can be fitted to existing chimneys where they capture CO2 for removal and storage. Not only are the new membranes efficient, they are also relatively cheap to produce. They are already being tested on brown coal power stations in Victoria’s La Trobe Valley, Colin says. “We are hoping these membranes will cut emissions from power stations by up to 90 per cent.”
Tamara Davis is looking for dark energy. Credit: timothyburgess.net
In 1998 astronomers made an astonishing discovery—the expansion of the Universe is accelerating. The discovery required a complete rethink of the standard model used to explain how the Universe works.
“Now we know that stars, planets, galaxies and all that we can see make up just four per cent of the Universe,” says Dr Tamara Davis, a University of Queensland astrophysicist.
“About 23 per cent is dark matter. The balance is thought to be dark energy, which we know very little about.”
John O’Sullivan with a prototype of the revolutionary phased array feed for the ASKAP. Credit: Chris Walsh, Patrick Jones Photo Studio
CSIRO’s Dr John O’Sullivan, winner of the 2009 Prime Minister’s Prize for Science, is now working on the next generation of radio telescopes.
John’s latest efforts are directed towards the development of an innovative radio camera or ‘phased array feed’ with a uniquely wide field-of-view for the Australian SKA Pathfinder (ASKAP) radio telescope.
