The Dynamic Universe

Tara Murphy Lynch
Associate Professor Tara Murphy Dr Christene Lynch
Theme Leader Theme Scientist

The Universe is a changing and violent place. These changes are often subtle, brief or difficult to identify, but can provide us with a unique window onto the fundamental physical processes that drive the evolution of the cosmos. For example, supernova explosions and gamma-ray bursts, two related phenomena that were both discovered through their time-varying behaviour, have spawned entire new fields of study on the formation of black holes, the origin of the chemical elements, the generation of cosmic rays, and the acceleration of the Universe’s expansion.

However at radio and optical wavelengths, tremendous signal-processing overheads have left the time-varying sky largely unexplored. In CAASTRO, we are carrying out the first all-sky censuses of the variable and transient sky coordinated between both radio and optical wavelengths. This ambitious undertaking is made possible by combining our team’s formidable multi-wavelength experience with the simultaneous availability of a suite of novel Australian investigations: we are carrying out all-sky surveys for radio variability with the Murchison Widefield Array (MWA), the Australian Square Kilometre Array Pathfinder (ASKAP), a newly-instrumented Parkes telescope, and the Square Kilometre Array Molonglo Prototype (SKAMP), all accompanied by continuous monitoring of the entire southern optical sky using SkyMapper.

These experiments will together allow us to study the changing sky over a wider field of view, at higher sensitivity and over a wider range of time scales than has ever previously been possible. CAASTRO’s all-sky multi-wavelength approach to transients is based around a carefully planned set of surveys performed using innovative and advanced instrumentation. We are implementing new software algorithms and pipelines that can efficiently identify variables and transients buried in the vast amounts of data generated by our surveys; we will be processing this explosion of information using the supercomputers at the Pawsey High Performance Computing Centre for SKA Science.

Watch the theme video profile as presented by Professor Matthew Bailes. The projects associated with CAASTRO's Dynamic Universe research theme include:

Pulsars: Fast spinning neutron stars that can improve our understanding of gravitational waves.
FRBs (Fast radio bursts): The search for radio pulses of which the origin is yet to be discovered.
Optical Transients: Looking for dynamic events in the visible portion of the spectrum
Slow Transients: Looking for variability over durations from minutes to years