The Polarisation Sky Survey of the Universe’s Magnetism (POSSUM): Science goals and survey description

Abstract The Australian SKA Pathfinder (ASKAP) offers powerful new capabilities for studying the polarised and magnetised Universe at radio wavelengths. In this paper, we introduce the Polarisation Sky Survey of the Universe’s Magnetism (POSSUM), a groundbreaking survey with three primary objectives: (1) to create a comprehensive Faraday rotation measure (RM) grid of up to one million compact extragalactic sources across the southern $\sim50$ % of the sky (20,630 deg $^2$ ); (2) to map the intrinsic polarisation and RM properties of a wide range of discrete extragalactic and Galactic objects over the same area; and (3) to contribute interferometric data with excellent surface brightness sensitivity, which can be combined with single-dish data to study the diffuse Galactic interstellar medium. Observations for the full POSSUM survey commenced in May 2023 and are expected to conclude by mid-2028. POSSUM will achieve an RM grid density of around 30–50 RMs per square degree with a median measurement uncertainty of $\sim$ 1 rad m $^{-2}$ . The survey operates primarily over a frequency range of 800–1088 MHz, with an angular resolution of 20” and a typical RMS sensitivity in Stokes Q or U of 18 $\mu$ Jy beam $^{-1}$ . Additionally, the survey will be supplemented by similar observations covering 1296–1440 MHz over 38% of the sky. POSSUM will enable the discovery and detailed investigation of magnetised phenomena in a wide range of cosmic environments, including the intergalactic medium and cosmic web, galaxy clusters and groups, active galactic nuclei and radio galaxies, the Magellanic System and other nearby galaxies, galaxy halos and the circumgalactic medium, and the magnetic structure of the Milky Way across a very wide range of scales, as well as the interplay between these components. This paper reviews the current science case developed by the POSSUM Collaboration and provides an overview of POSSUM’s observations, data processing, outputs, and its complementarity with other radio and multi-wavelength surveys, including future work with the SKA.

Authors

Institutions

Publication Details

Journal
Publications of the Astronomical Society of Australia
Published
2025-01-01
DOI
https://doi.org/10.1017/pasa.2025.10031
Citations
7
Primary Topic
Astronomy and Astrophysical Research
Type
article
Field-Weighted Citation Impact
8.34

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

The Polarisation Sky Survey of the Universe’s Magnetism (POSSUM): Science goals and survey description

Sanja Lazarević, Erik Osinga, T. L. Landecker, Yik Ki et al.
7 citations
Publications of the Astronomical Society of Australia
Astronomy and Astrophysical Research
8.34
article

The Polarisation Sky Survey of the Universe’s Magnetism (POSSUM): Science goals and survey description

Sanja Lazarević, Erik Osinga, T. L. Landecker, Yik Ki, Andrew Hopkins, R. P. Norris, N. M. McClure‐Griffiths, Ayush Pandhi, J. P. Leahy, Cameron L. Van Eck, Jane Kaczmarek, Tao An, Takuya Akahori, A. J. M. Thomson, C. Sobey, Sui Ann Mao, G. Heald, J. Price, A. Willis, Chakali Eswaraiah, Vasundhara Shaw, S. M. Bradbury, L. Rudnick, B. M. Gaensler, J. M. Stil, G. Gürkan, E. Carretti, P. Ryder, Sebastian Hutschenreuter, C. Stuardi, J. D. Livingston, A. Bracco, Shinsuke Ideguchi, C. S. Anderson, S. Jaswanth, R. Kothes, S. P. O’Sullivan, Ao Shen, A. D. Amaral, Jennifer West, Wasim Raja, D. A. Leahy, Velibor Velović, T. J. Galvin, F. Loi, C. J. Riseley, T. Vernstrom, T. A. Enßlin, Amit Seta, A. R. Taylor, M. Haverkorn, S Lyla Jung, M. Brüggen, Xiaohui Sun, Lerato Baidoo, Shannon Vanderwoude, E. Alexander, Joshua R. Marvil, D. Alonso-López, Gupta Upasana
article en
7 citations

Abstract

Abstract The Australian SKA Pathfinder (ASKAP) offers powerful new capabilities for studying the polarised and magnetised Universe at radio wavelengths. In this paper, we introduce the Polarisation Sky Survey of the Universe’s Magnetism (POSSUM), a groundbreaking survey with three primary objectives: (1) to create a comprehensive Faraday rotation measure (RM) grid of up to one million compact extragalactic sources across the southern $\sim50$ % of the sky (20,630 deg $^2$ ); (2) to map the intrinsic polarisation and RM properties of a wide range of discrete extragalactic and Galactic objects over the same area; and (3) to contribute interferometric data with excellent surface brightness sensitivity, which can be combined with single-dish data to study the diffuse Galactic interstellar medium. Observations for the full POSSUM survey commenced in May 2023 and are expected to conclude by mid-2028. POSSUM will achieve an RM grid density of around 30–50 RMs per square degree with a median measurement uncertainty of $\sim$ 1 rad m $^{-2}$ . The survey operates primarily over a frequency range of 800–1088 MHz, with an angular resolution of 20” and a typical RMS sensitivity in Stokes Q or U of 18 $\mu$ Jy beam $^{-1}$ . Additionally, the survey will be supplemented by similar observations covering 1296–1440 MHz over 38% of the sky. POSSUM will enable the discovery and detailed investigation of magnetised phenomena in a wide range of cosmic environments, including the intergalactic medium and cosmic web, galaxy clusters and groups, active galactic nuclei and radio galaxies, the Magellanic System and other nearby galaxies, galaxy halos and the circumgalactic medium, and the magnetic structure of the Milky Way across a very wide range of scales, as well as the interplay between these components. This paper reviews the current science case developed by the POSSUM Collaboration and provides an overview of POSSUM’s observations, data processing, outputs, and its complementarity with other radio and multi-wavelength surveys, including future work with the SKA.

Publications of the Astronomical Society of AustraliaVol. 42
Australian National University (AU), Herzberg Institute of Astrophysics (CA), Indian Institute of Science Education and Research Kolkata (IN), Commonwealth Scientific and Industrial Research Organisation (AU), University of Vienna (AT), Australia Telescope National Facility (AU), University of Minnesota (US), University of Leeds (GB), University of Hertfordshire (GB), Radboud University Nijmegen (NL), University of Cape Town (ZA), Universität Hamburg (DE), Indian Institute of Science Education and Research Mohali (IN), University of Calgary (CA), The University of Western Australia (AU), University of California, Santa Cruz (US), University of Toronto (CA), Yunnan University (CN), Chinese Academy of Sciences (CN), National Radio Astronomy Observatory (US), Université Paris Sciences et Lettres (FR), Shanghai Astronomical Observatory (CN), University of Minnesota System (US), University of Manchester (GB), Indian Institute of Science Education and Research, Bhopal (IN), University of Oxford (GB), Institute of Astrophysics and Space Sciences (PT), Max Planck Institute for Astrophysics (DE), Swedish e-Science Research Centre (SE), Canadian Institute for Theoretical Astrophysics (CA), Indian Institute of Science Education and Research Berhampur (IN), Istituto di Radioastronomia di Bologna (IT), Indian Institute of Science Education and Research, Tirupati (IN), Osservatorio Astronomico di Cagliari (IT), Astronomical Observatory (RS), Perth Observatory (AU), Max Planck Institute for Radio Astronomy (DE), National Research Council Canada (CA), National Astronomical Observatory of Japan (JP), International Centre for Radio Astronomy Research (AU), National Astronomical Observatories (CN), Western Sydney University (AU), University of the Western Cape (ZA), Ruhr University Bochum (DE), Macquarie University (AU)
National Aeronautics and Space Administration, Science and Industry Endowment Fund, Comunidad de Madrid, Space Telescope Science Institute, UK Research and Innovation, Australian Government, European Commission, Commonwealth Scientific and Industrial Research Organisation, Deutsche Forschungsgemeinschaft, Canada Research Chairs, University of Toronto, Government of Western Australia, Alliance de recherche numérique du Canada, Canadian Space Agency, Natural Sciences and Engineering Research Council of Canada, Science and Technology Facilities Council, European Regional Development Fund, Agencia Estatal de Investigación
Openalex Percentile: Top 3%
Astronomy and Astrophysical Research
8.34
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.