I am a third year PhD student in Astronomy at the Institute of Astronomy, University of Cambridge. I enjoy working at the intersection between astrophysics and cosmology, learning how to disentangle the impact of galaxy formation physics on our measurements of cosmology. My research focuses on understanding baryonic feedback and its role as a dominant systematic in weak lensing and galaxy surveys, capable of significantly limiting the precision of (and potentially biasing) cosmological constraints. Early in my PhD, I co-led the first joint analysis of DES Y3 cosmic shear and BOSS+ACT kSZ measurements (WL+kSZ), where we provided observational evidence suggesting that baryonic feedback is more extreme than commonly implemented in current cosmological hydrodynamical simulations (Bigwood & Amon+24). More recently, in order to investigate whether such extreme feedback could arise in a physical galaxy formation model, I led work exploring a vast number of empirical AGN feedback models within the FABLE hydrodynamical simulation suite. This led to the development of a novel AGN feedback model, XFABLE, which demonstrates good agreement with our WL+kSZ constraints on extreme feedback, while simultaneously maintaining consistency with all key galaxy, group, and cluster properties (Bigwood+25). This work demonstrated that existing feedback models in hydrodynamical simulations may in fact underestimate the impact of feedback, and XFABLE offers a physically motivated mechanism for the longer-range AGN feedback that kSZ observations are hinting at. Currently, I am interested in improving the interpretation of kSZ observations as a probe of feedback and understanding their use as a benchmark for hydrodynamical simulations.
Highlighted publications
The case for large-scale AGN feedback in galaxy formation simulations: insights from XFABLE - Bigwood et al. 2025 (submitted to MNRAS)
Weak lensing combined with the kinetic Sunyaev Zel'dovich effect: A study of baryonic feedback - Bigwood & Amon et al. 2024 (MNRAS)
Evidence for episodic black hole growth of reionization-era quasars observed with Magellan/FIRE - Bigwood et al. 2024 (MNRAS)
Career
PhD in Astronomy: Institute of Astronomy, University of Cambridge (2022-present)
MPhys Physics & Astronomy: Durham University (2018-2022)
Awards and Prizes
John Barrow Travel Award (Clare Hall, University of Cambridge, 2024)
D. A. Wright Prize for Outstanding Performance in Final Honours MPhys Physics and Astronomy (Durham University, 2022)
Level 4 Prize for Theoretical Astrophysics (Durham University, 2022)
Durham Physics Award for Outstanding Achievement (Durham University, 2020, 2021, 2022)
John Simpson Greenwell Memorial Fund (Durham University, 2020, 2021, 2022)