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Despite the fundamental nature of cosmic magnetic fields, many questions remain regarding their origin, evolution, and structure. We are able to illuminate these otherwise invisible fields through observations of background polarised radio sources. By measuring the Faraday rotation this polarised emission experiences along the line of sight, we are able to reconstruct the magneto-ionic structure of foreground features, such as the Milky Way Galaxy. This technique would also be applicable to smaller foreground objects, such as galaxies and clusters, however, we are typically limited by the on-sky density of background sources detected by a given radio survey. On behalf of the RACS team, I will provide an overview of observations from the Rapid ASKAP Continuum Survey (RACS); the first all-sky survey undertaken by the Australian SKA Pathfinder (ASKAP). RACS is now the state-of-the-art radio-frequency survey of the Southern sky, with a noise-level of ~ 300 micro Jy/beam, a resolution of 25 arcsec, and 2.1 million sources detected in total intensity at 888 MHz. Through a collaboration between the observatory and the Polarisation Sky Survey of the Universes Magnetism (POSSUM) survey teams, SPICE-RACS will catalogue linearly polarised sources from RACS and deliver a background polarised source density 3-5x higher than the current state of the art. I will present the first data release of SPICE-RACS. This catalogue contains ~6000 polarised radio sources, imaged at 25 arcsec, over 1300 square degrees towards the nearby Spica HII region. I will describe our first science results derived from this catalogue, and the future plans for SPICE-RACS. |
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