Swinburne University of Technology astrophysicists have just booked themselves a ticket on the world’s biggest ‘time machine’, capable of reaching back 12 billion years to the earliest phases of the universe when galaxies were first forming.
And, in a remarkable and probably world-first concept, they are proposing to take Swinburne students and staff and the Australian public along for a ride that could include a glimpse of some of the biggest ‘traffic accidents’ in the universe.
In a major advance for Australian optical and infrared astronomy, Swinburne has recently signed an agreement entitling its astronomers to 15 nights’ exclusive viewing each year on the world’s largest and most powerful optical telescopes – the mighty pair of 10-metre Keck instruments atop Mauna Kea in Hawaii. This represents a major increase in viewing capacity on the world’s largest telescopes for Australian astronomy in total and is part of Vice-Chancellor Ian Young’s plan to improve the impact of Swinburne’s research through major investments in infrastructure in its chosen areas of research concentration.
The arrangement opens a window not only into the earliest universe, but also the progressive evolution and distribution of its galaxies through time, says Professor Karl Glazebrook of Swinburne’s Centre for Astrophysics and Supercomputing. It creates a rare opportunity to see whether some of the fundamental rules that govern its behaviour have changed. The telescope functions as a time machine because it is seeing events that occurred many billions of years ago. This is how long it has taken for the light emitted from these events to reach our galaxy, the Milky Way, and planet Earth.
"The Keck Telescope has been at the forefront of global optical astronomy for the past 15 years," Professor Glazebrook says. "Its collecting area is almost twice that of the Gemini Telescopes Australians have mainly been using till now. With the latest advances in laser adaptive optics, its images are even crisper than those of the Hubble Space Telescope.
"As part of the exchange, Caltech astronomers, in collaboration with Swinburne astronomers, will have greater access to state-of-the-art supercomputing instrumentation on Australia’s radio telescope facilities. Joint symposia are being planned, as well as student exchanges."
The agreement with Caltech, one of the two major partners in the Keck Telescopes, offers Swinburne astronomers an unparalleled opportunity to study evolving cosmological phenomena over time, in detail and in depth.
Keen to share their good fortune, the Swinburne astrophysicists are already discussing a revolutionary idea – to erect a large screen in a public location on the Hawthorn campus that will display real-time images straight from the telescope during the observations, so that passers-by can share the wonder and excitement of looking back in time to the early universe and see what the researchers are actually studying.
For the centre’s director, Professor Matthew Bailes, having access to the world’s very best instruments is an essential part of Swinburne’s plans to be at the forefront of global astrophysics research.
"We now have the right combination of outstanding individuals and phenomenal technology to achieve rapid, high-impact discovery," Professor Bailes says. "The Keck Telescope’s instrumentation is a portal to the early universe. It will enable us to provide undergraduates with a view of what the universe was like billions of years ago from the remote operations centre to be established on campus."
Karl Glazebrook’s own project will explore the state of galaxies at the peak of their formation epoch, about eight billion years ago. With galaxies hand-picked from a previous deep space survey, he and his students will study the rotational velocities and mass distributions of these youthful galaxies in a bid to solve one of the great riddles of galactic formation.
"There is a surprising abundance of massive galactic systems, both star-forming and passive, in these early epochs of the universe," Professor Glazebrook says. "This contradicts our current theoretical models, which suggest mega-galaxies should be fewer at this time – as they should only have accreted, or ‘clumped together’, later on due to their gravitational attraction to one another.
"This observation challenges the models subscribed to by many astronomers in which galaxies build up hierarchically by merging. It implies that star formation in massive clumps of dark matter started early, was highly efficient and was later strongly quenched," he says. "The reasons why there should be such a sharp peak in star formation early on are unclear and this is one of the questions we hope to answer."
Another important question is how the combined mass of all the stars visible in a galaxy using optical telescopes relates to the galaxy’s total mass. The ratio of seen to unseen mass is a key determinant of the galaxy formation process itself, he explains.
The power of the Keck instrument will enable the astronomers to peer into the heart of these distant objects and determine whether the swirling motion of their stars is orderly or chaotic, whether stars are flowing in or out of the galactic discs and whether the discs themselves are well formed or irregular at this point in their life history.
Of particular value in this quest is the Keck’s adaptive optics, which enable it to pierce the Earth’s atmosphere with unprecedented precision, eliminating the ‘twinkle’ or distortion the atmosphere causes to distant shining objects.
A second major project on the Keck is that of Professor Warrick Couch, an Australian Research Council (ARC) Professorial Research Fellow, who will be studying galaxies at a somewhat more ‘mature’ stage of their development, about six billion years ago.
"We won’t just be looking at the biggest and the brightest galaxies, but also at the more average ones, similar to our own Milky Way," Professor Couch says. "We will be asking which types evolve the fastest – the massive ones or the much smaller ones.
"And we will be examining the rich galactic clusters, where many galaxies are coming together, and trying to measure the speed at which their stars and gas rotate, and see how this is affected by the proximity of others."
Such studies, he hopes, will throw more light on how the universe is evolving, not spreading out evenly as was originally thought, but into clusters of galaxies interspersed by vast realms of empty space and thin tendrils of matter.
"Galactic clusters are bound together by gravity and this defines the structure of the universe," Professor Couch explains. "Gravitational instability builds structure, collapses, creates filaments and voids."
The pinnacle of this process occurs when two large galactic groups merge to form an even bigger cluster – the biggest ‘traffic accident’ in the universe. So far, about a dozen of these monster phenomena have been observed, and Professor Couch is keen to study in detail what happens to the individual galaxies within them as the majestic ‘smash’ proceeds.
Both Professors Glazebrook and Couch are ‘HiCi’ scientists, meaning they are in the top 0.5 per cent in the world for having their research cited by other astronomers. Their acquisition of so much more time on the Keck instrument opens the way for Australian astronomy to have an even greater impact on global science – and reinforce the case for building the world’s next giant radioastronomy device, the Square Kilometre Array, in this country.
A third project using Keck is run by Dr Michael Murphy, a Queen Elizabeth II Research Fellow, who will be using a high-resolution spectrometer called HIRES to study the spectra of quasars, close and far, to see whether some of the fundamental constants of the universe have in fact changed since earliest times.
Confirming or refuting this highly controversial proposition – that the rules governing the universe may themselves be still evolving – requires the collection of the most light possible, and no instrument is better suited to this task than the Keck.
The Swinburne team’s precious exclusive time on Keck, one of the largest research investments made by the university in recent years, will begin as early as July this year, says Professor Glazebrook. Aware of the keen interest the work is likely to generate, the team has been exploring ideas for sharing some of the excitement of discovery.
One of these is to beam whatever the team is observing at the time on the Keck Telescope direct to a large screen on Swinburne’s Hawthorn campus, where others can savour some of the wonder of being able to travel back several billion years to a younger universe that existed even before our own sun condensed.
"There are a few issues to be resolved, but in principle it is do-able," Professor Glazebrook says. "An advantage is that night-time in Hawaii, when observation takes place, is afternoon in Australia, and ideal for the public to see what’s going on. Ultimately, too, we hope to be able to actually control the Keck Telescopes from Swinburne itself."
By putting Australia online to the ancient universe, the Swinburne team hopes to stimulate enthusiasm for astronomy that will lead to many more important discoveries by Australian astronomers.
A story provided by Swinburne Magazine. This article is under copyright; permission must be sought from Swinburne Magazine to reproduce it.