© “Marion Dingo, POSSUM, 2023, acrylic on canvas”

The Australian SKA Pathfinder (ASKAP) is designed to dramatically increase our ability to rapidly survey the radio sky via a broad portfolio of science programs. ASKAP’s unique survey capabilities will be used to transform our understanding of astrophysical magnetic fields through two major projects. First, SPICE-RACS, the linear polarization counterpart to the Rapid ASKAP Continuum Survey (RACS), will provide a major step forward in our view of the magnetised sky particularly from the Southern hemisphere, with a major data release nearing completion. On a somewhat longer timeframe we will subsequently deliver an even clearer view with POSSUM, the Polarisation Sky Survey of the Universe’s Magnetism. Commensal with both the EMU radio continuum survey and the WALLABY HI survey, POSSUM is utilising sensitive spectopolarimetric data to generate a dense and precise grid of up to about a million background Faraday rotation measures that probe gas and magnetic fields in foreground objects. POSSUM aims to revolutionise our understanding of magnetic fields and their role in fundamental physical processes across a wide range of scales: in the interstellar medium; the large-scale Milky Way and halo; external galaxies dominated by star formation, active galactic nuclei or merger activity; galaxy clusters; the cosmic web; and the intergalactic medium. At a deeper level, POSSUM seeks to reveal how the first magnetic fields were generated, and to understand the processes that organised and strengthened those fields to the present day. In this talk I will briefly remark on overall ASKAP status, summarise the science aims of the POSSUM project, and then highlight results from both SPICE-RACS and POSSUM. I’ll conclude by discussing prospects for magnetism science with the SKA.

CSIRO, Australia's national science agency, commissioned a series of works by Wajarri Yamaji artists to celebrate ASKAP's Survey Science Projects. POSSUM by Wajarri artist Marion Dingo, is one in this series.