Institute of Astronomy

- Julia Sisk-Reynes


Office: Obs O14
Office Tel: (01223) 337531
More Info (Internal)



I am interested in astrophysical searches of light Axion-Like Particles (ALPs). I currently investigating the projected sensitivity of next-generation X-ray missions -in particular, the Athena X-Ray Observatory and the Advanced X-ray Imaging Satellite (AXIS)to constraining light ALPs. 

Selected papers

First author 

Evidence for a moderate spin from X-ray reflection of the high-mass supermassive black hole at the centre of the cluster-hosted quasar H1821+643 - J. Sisk-Reynés, Christopher S. Reynolds, James H. Matthews, et al. (2022)

New constraints on light Axion-Like Particles using Chandra Transmission Grating Spectroscopy of the powerful cluster-hosted quasar H1821+643 - J. Sisk-Reynés, James H. Matthews, Christopher S. Reynolds, et al. (2021)


How do Magnetic Field Models Affect Astrophysical Limits on Light Axion-like Particles? An X-ray Case Study with NGC 1275 - James H. Matthews, Christopher S. Reynolds, M.C. David Marsh, J. Sisk-Reynés, Payton E. Rodman (2022)


2020 - present. University of Cambridge - Undergraduate Supervisions: Astrophysical Fluid Dynamics (Part II, 3rd year) and Mathematics 1A (Natural Sciences, 1st year).

2019. University of Manchester - Particle physics summer research: On direct dark matter detection at the DarkSide-20k liquid Argon experiment (under D. Price and A. Szelc).

2018 - 2019: Teaching placements in the UK: Teach First Insight Programme (2019), Teach Physics Internship by the Ogden Trust (2018).  


2020 - present: Ph.D. in Astronomy, Institute of Astronomy, The University of Cambridge (under C. Reynolds).

2016 - 2020: MPhys (Hons) Physics, The University of Manchester.

Awards and Prizes

2020 - Stellify Award (by the University of Manchester): for contributions and commitment as an undergraduate student in the areas of volunteering, leadership and ethical grand challenges.

Press releases

June 2022 - Chandra Shows Giant Black Hole Spins Slower Than Its Peers 

Upcoming talks 

November 2022 - 3rd Scientific Conference dedicated to the Athena X-ray Observatory "Exploring the Hot and Energetic X-ray Universe" (Barcelona, Spain)

Scientific conferences

September 2022 - Contributed talk at the Progress in Axion Theory and Experiment Workshop (Durham, UK)

June 2022 - Contributed talk at the European Astronomical Society Annual Conference (Valencia, Spain)

June 2022 - Contributed talk at the XMM-Newton "Black Holes under the X-ray microscope" (ESAC, Madrid, Spain)

May 2022 - Contributed talk at the "New Results in X-ray Astronomy Annual UK meeting" (Leicester, UK)

Page last updated: 9 September 2022 at 08:21