A full list of publications, along with selected conference abstracts, can be found at NASA/ADS.

Refereed Publications

  • Speeding up Gravitational Lens Mass Models with Machine Learning: Applications in X-ray Astronomy.
    Ostridge, Alex; Martínez-Galarza, Rafael; Sisk-Reynés, Júlia M., Schwartz, Daniel A. & Barnacka, A.
    Paper by a student whom I have mentored.
    September 2026, MNRAS, 551, 2, id.stag1417, 17 pp.
    Publisher

  • Spin Demographics of Active Supermassive Black Holes: Updated Estimates from X-ray reflection and Future opportunities.
    Sisk-Reynés, Júlia M., et al.
    Invited review.
    Galaxies, May 2026, 14(3), 50.
    Publisher
    Github repository

  • Determining the spatial origin of X-ray and optical emission in the z= 3.1 strongly lensed radio-quiet quasar GraL J065904.1+162909 to hundreds of parsecs.
    Sisk-Reynés, Júlia M., et al.
    March 2026, ApJ, 999, 2, id.215
    Publisher

  • Getting more out of black hole superradiance: a statistically rigorous approach to ultralight boson constraints from black hole spin measurements.
    Hoof, Sebastian; Marsh, David J. E.; Sisk-Reynés, Júlia M., Matthews, James H. & Reynolds, Christopher S.
    February 2026, MNRAS, 546, 2, id.staf1564, 16 pp.
    Publisher

  • Evidence for supermassive black hole binaries.
    Krause, Martin G. H., et al., including Sisk-Reynés, Júlia M.
    November 2025, PASA, 42, id.e162, 18 pp.
    Publisher

  • The Advanced X-ray Imaging Satellite (AXIS) Community Science Book.
    Koss, Michael, et al., including Sisk-Reynés, Júlia M.
    October 2025, arXiv:2511.00253.
    arXiv

  • The detergent particle.
    Sisk-Reynés, Júlia M.
    Invited scientfic review article.
    December 2024, Royal Astronomical Society’s Astronomy and Geophysics magazine.
    Publisher

  • Physics Beyond the Standard Model with Future X-Ray Observatories: Projected Constraints on Very-light Axion-like Particles with Athena and AXIS.
    Sisk-Reynés, Júlia M., et al.
    June 2023, ApJ, 951, 1, id.5, 17 pp.
    Publisher
    Press Release

  • Current and Future constraints on Very-Light Axion-Like Particles from X-ray observations of cluster-hosted Active Galaxies.
    Sisk-Reynés, Júlia M., Reynolds, Christopher S., & Matthews, James H.
    April 2023, Memorie della Società Astronomica Italiana, 94, 3, p.26.
    arXiv

  • Evidence for a moderate spin from X-ray reflection of the high-mass supermassive black hole in the cluster-hosted quasar H1821+643.
    Sisk-Reynés, Júlia M., et al.
    June 2022, MNRAS, 514, 2, pp. 2568–2580.
    Publisher
    Press Release

  • How Do Magnetic Field Models Affect Astrophysical Limits on Light Axion-like Particles? An X-Ray Case Study with NGC 1275.
    Matthews, James H.; Marsh, M. C. David; Reynolds, Christopher S., Sisk-Reynés, Júlia M. & Rodman, Payton E.
    May 2022, ApJ, 930, 1, id.90, 17 pp.
    Publisher

  • New constraints on light axion-like particles using Chandra transmission grating spectroscopy of the powerful cluster-hosted quasar H1821+643.
    Sisk-Reynés, Júlia M., et al.
    February 2022, MNRAS, 510, 1, pp.1264-1277.
    Publisher