The FLAMINGO project: cosmological hydrodynamical simulations for large-scale structure and galaxy cluster surveys

Schaye, Joop; Kugel, Roi; Schaller, Matthieu; Helly, John C.; Braspenning, Joey; Elbers, Willem; McCarthy, Ian G.; van Daalen, Marcel P.; Vandenbroucke, Bert; Frenk, Carlos S.; Kwan, Juliana; Salcido, Jaime; Bahe´, Yannick M.; Borrow, Josh; Chaikin, Evgenii; Hahn, Oliver; Husko, Filip; Jenkins, Adrian; Lacey, Cedric G.; Nobels, Folkert S. J.

Abstract

We introduce the Virgo Consortium’s FLAMINGO suite of hydrodynamical simulations for cosmology and galaxy cluster
physics. To ensure the simulations are sufficiently realistic for studies of large-scale structure, the subgrid prescriptions for
stellar and AGN feedback are calibrated to the observed low-redshift galaxy stellar mass function and cluster gas fractions. The
calibration is performed using machine learning, separately for each of FLAMINGO’s three resolutions. This approach enables
specification of the model by the observables to which they are calibrated. The calibration accounts for a number of potential
observational biases and for random errors in the observed stellar masses. The two most demanding simulations have box sizes
of 1.0 and 2.8 Gpc on a side and baryonic particle masses of 1 × 108 and 1 × 109 M, respectively. For the latter resolution,
the suite includes 12 model variations in a 1 Gpc box. There are 8 variations at fixed cosmology, including shifts in the stellar
mass function and/or the cluster gas fractions to which we calibrate, and two alternative implementations of AGN feedback
(thermal or jets). The remaining 4 variations use the unmodified calibration data but different cosmologies, including different
neutrino masses. The 2.8 Gpc simulation follows 3 × 1011 particles, making it the largest ever hydrodynamical simulation run
to z = 0. Light-cone output is produced on-the-fly for up to 8 different observers. We investigate numerical convergence, show
that the simulations reproduce the calibration data, and compare with a number of galaxy, cluster, and large-scale structure
observations, finding very good agreement with the data for converged predictions. Finally, by comparing hydrodynamical and
‘dark-matter-only’ simulations, we confirm that baryonic effects can suppress the halo mass function and the matter power
spectrum by up to ≈20 per cent.

Citation

Schaye, J., Kugel, R., Schaller, M., Helly, . J. C., Braspenning, J., Elbers, W., …Nobels, F. S. J. (2023). The FLAMINGO project: cosmological hydrodynamical simulations for large-scale structure and galaxy cluster surveys. Monthly Notices of the Royal Astronomical Society, 526(4), 4978–5020. https://doi.org/10.1093/mnras/stad2419

• Journal Article Type: Article
• Acceptance Date: Aug 4, 2023
• Online Publication Date: Aug 18, 2023
• Publication Date: 2023-12
• Deposit Date: Jan 30, 2024
• Publicly Available Date: Jan 30, 2024
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 526
• Issue: 4
• Pages: 4978–5020
• DOI: https://doi.org/10.1093/mnras/stad2419
• Public URL: https://durham-repository.worktribe.com/output/2187100