Research

The CAASTRO team is delivering transformational new science by bringing together unique expertise in radio astronomy, optical astronomy, theoretical astrophysics and computation, and by coupling these capabilities with powerful Australian and international facilities. We are pursuing our research programs within three interlinked scientific themes under the Evolving, Dynamic and Dark Universes, each of which can be addressed with the all-sky perspective provided by new wide-field telescopes:

The Evolving Universe:

When did the first galaxies form, and how have they then evolved? These are questions which CAASTRO researchers are addressing through new observations of the redshifted 21cm line at the Epoch of Reionisation when the first galaxies were being formed. These observations are being guided by powerful cosmological simulations which attempt to reproduce the heating effects of the first stars and galaxies. CAASTRO researchers are also using 21cm, radio and optical observations of galaxies in the more nearby Universe, again aided by powerful simulations, to discover how galaxies evolve over time. The role of gas and stars in galaxies is especially important in determining their formation and evolution timescales.

The Dynamic Universe:

What is the high-energy physics that drives rapid change in the Universe? CAASTRO researchers are conducting world-class experiments with telescopes such as Parkes, MWA and Molonglo to discover new pulsars, fast radio bursts, and other time-variable objects. Objects which change their brightness on a short timescale are usually extremely compact, and they are excellent probes for studying high-energy physics. In the case of orbiting pulsars, they are also excellent laboratories for testing gravitational theory. Other time-variable objects tell us about the physical state of the interstellar medium, and the physics which drives the formation of jets in compact accreting objects.

The Dark Universe:

What are the Dark Energy and Dark Matter that dominate the cosmos? These can be probed by comparing the distances and redshifts of objects such as supernovae or galaxies. Such a comparison allows precision cosmological measurements to be made of the accelerating Universe, and is a probe of the physics that underlies its formation. It also allows us to directly measure concentrations of dark matter by their effect on the motions of galaxies.

 

Some of the world-leading facilities and surveys that CAASTRO is using and conducting in order to study the Evolving, Dynamic and Dark Universe include:


Photo: MWA antenna tile, consisting of 16 cross dipoles, on site at Boolardy,
Western Australia (photo credit:
Jacqueline Hewitt)