Probing ordered magnetic fields in galaxies across cosmic time

@misc{chen2026probing,
  title = {{Probing ordered magnetic fields in galaxies across cosmic time}},
  author = {Jianhang Chen and Melanie Kaasinen and Enrique Lopez-Rodriguez and Wouter Vlemmings and Andrea Lapi and Rosita Paladino and Hannah Stacey and Pierre Cox and Tom J. L. C. Bakx and Andreas Faisst and Jacqueline Hodge and Elisabete da Cunha and Leindert A. Boogaard and Dieu D. Nguyen and Adarsh Kumar and Leo Wang and Gergö Popping and Willem de Roo and Simona Vegetti},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.20711},
  eprint = {2610.20711},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.20711},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Probing ordered magnetic fields in galaxies across cosmic time
AU  - Jianhang Chen
AU  - Melanie Kaasinen
AU  - Enrique Lopez-Rodriguez
AU  - Wouter Vlemmings
AU  - Andrea Lapi
AU  - Rosita Paladino
AU  - Hannah Stacey
AU  - Pierre Cox
AU  - Tom J. L. C. Bakx
AU  - Andreas Faisst
AU  - Jacqueline Hodge
AU  - Elisabete da Cunha
AU  - Leindert A. Boogaard
AU  - Dieu D. Nguyen
AU  - Adarsh Kumar
AU  - Leo Wang
AU  - Gergö Popping
AU  - Willem de Roo
AU  - Simona Vegetti
PY  - 2026
DA  - 2026/10/14
PB  - arXiv
DO  - 10.48550/arxiv.2610.20711
UR  - https://arxiv.org/abs/2610.20711
AB  - Magnetic fields are dynamically important across many astronomical environments, yet their origin, strength, and evolution over cosmic time remain poorly understood. Ordered magnetic fields are ubiquitous in the nearby Universe, as revealed by a range of observational techniques, but evidence for their existence at cosmological distances is scarce. Recent ALMA detections of polarised dust emission indicate that galactic-scale ordered magnetic fields, spanning up to kiloparsec scales, were already present in massive star-forming galaxies at redshifts up to z∼5.6. This white paper argues that the ALMA2040 concept -- with its nearly tenfold improvement in sensitivity and angular resolution, and full-polarisation capability extended to higher-frequency bands -- will open up the study of cosmic magnetism in the early Universe. We identify four science drivers: constraining the dynamos that generate galactic-scale ordered fields, measuring the strength of early magnetic fields, connecting magnetic fields to galaxy evolution across cosmic time, and constraining dust grain properties through the polarised spectral energy distribution. We summarise the corresponding requirements in angular resolution, spectral coverage, and sensitivity, and discuss synergies with next-generation telescopes.
ER  -