Some astronomical questions can only be answered by looking at the whole sky all at once but the technology to do that doesn’t exist yet.
Enter the new ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), which launched today and brings together the best and brightest star-gazers, engineers and data managers in the country to design new ways of looking at the heavens.
CAASTRO will tackle three big research themes that have confounded astronomers for years:
- The Evolving Universe: When did the first galaxies form, and how have they evolved?
- The Dynamic Universe: What is the high-energy physics that drives rapid change in the Universe?
- The Dark Universe: What are the Dark Energy and Dark Matter that dominate the cosmos?
The centre will involve researchers from the University of Sydney, the Australian National University, the University of Melbourne, the University of Western Australia, Curtin University and Swinburne University of Technology.
In this edited Q+A, CAASTRO’s director, Professor Bryan Gaensler from the School of Physics at the University of Sydney, explains how the research centre will aim to go where no astrophysicist has gone before.
What is all-sky astrophysics?
Traditionally, the push in astronomy was to look at smaller and smaller parts of the sky in more and more detail with more powerful telescopes.
But there are certain fundamental questions of the universe that you can only answer by stepping back and by trying to image the whole sky at once.
First, we want to understand how the universe evolved and changed from when we first started and galaxies formed about 13 billion years ago to the present. We think we understand the beginning and we think we understand where we are at now but don’t really understand how we got from the beginning to now.
The second thing is the growing realisation that the universe changes quite dramatically on very short time scales. The universe explodes and flares and things suddenly appear and disappear. These explosions and catastrophes normally allow you to study extreme physics, to study things beyond anything you can study in the laboratory. There are fundamental things about space and matter and time that we can study by seeing the universe change.
The third thing we are studying is the dark universe: the slightly embarrassing fact that 95% of the universe is dark matter or dark energy and we have no idea what those are.
These are all questions that can be uniquely addressed by doing this very wide field astronomy and looking at the whole sky rather than individual objects.
What equipment is used to do all-sky astrophysics?
You have to build new types of telescopes with wide angle lenses. Essentially, you need to move from a zoom lens to a wide angle lens.
Even if you can build these new types of telescopes, the problem is you are now generating massive data sets. So you need to solve the computing problems involved in recording that data and processing that data and keeping up with this flood of data. If you can’t process it fast enough, the data piles up and you have nowhere to store it.
The problem with (existing telescopes such as) Hubble is it can only see a tiny part of the sky at once. It would be totally impractical with Hubble to try and map out a huge part of the sky, it would take you decades. You have to have telescopes that have very high quality, crisp, detailed images like Hubble but which have much wider fields of view.
That requires building new types of telescopes. We are very fortunate in Australia in that we are building these new telescopes that have enormous fields of view.
It’s not just about building these telescopes but making sure we don’t waste the opportunity we are going to have with these telescopes by providing the people and the brain power and the networks to make sure these telescopes do what they are designed to do.
So it’s going to be Australians who make discoveries rather than someone else.
We are also providing opportunities for students. By having experts from all over, we can offer courses and types of training that you couldn’t ever get in a single degree before.
We have money to hold workshops or run forums or design experiments. We can do things bigger and much more quickly than most people.
Normally, if someone has a good idea they write a grant, a year later they find out if they get the grant and then they can do it. By that time, someone else has already done it.
Because we have a seven year budget (of just over $4 million a year), if we have an idea we can do it. We can respond very quickly to a rapidly changing environment.
Why is this work important?
I think it’s pretty exciting that Australia has a seat at the international table. It’s not just people from other countries who are answering the really big questions. We are leading this. There’s a matter of national pride in the same way that wining a gold medal at the Olympics is.
We are asking really, really hard questions. We can’t just draw on existing technology and order new equipment from the catalogue, we have to design new approaches for things.
When you have to design a new approach, you inevitably come up with an idea that no one has ever thought before.
We expect we are going to come up with new ways of processing large data sets. The size of the data sets we have are way beyond what other fields are dealing with. In a few more years, genetics and meteorology and finance are going to have data sets like ours and we hope they are going to looking to us for efficient and powerful ways to process the data so they can deliver the conclusions and predictions they need to provide.
We like to think humans are about more than just surviving and reproducing. We can afford to look beyond that and think about our place in the cosmos, to think about where we are going and where we came from.