Sisk-Reynés, J., Matthews, J. H., Reynolds, C. S., Russell, H. R., Smith, R. N., & Marsh, M. C. (2022). New constraints on light axion-like particles using Chandra transmission grating spectroscopy of the powerful cluster-hosted quasar H1821+643. Monthly Notices of the Royal Astronomical Society, 510(1), 1264-1277. https://doi.org/10.1093/mnras/stab3464