HEALPix maps

The FLAMINGO simulation lightcone outputs include full-sky projected maps of particle properties (such as mass or x-ray luminosity) in concentric spherical shells around each observer. When a particle crosses the observer’s lightcone we determine which radial shell it is in and accumulate its contribution to the appropriate maps.

These maps use the HEALPix pixelisation scheme to divide the sky into pixels of equal area. The maps are provided at two resolutions. The highest resolution maps have an angular resolution of about 13 arcseconds (\(N_\mathrm{side}=16384\)). Since these large maps can be difficult to work with, we also provide down-sampled maps with an angular resolution of about 50 arcseconds (\(N_\mathrm{side}=4096\)).

Projected mass in shells
../_images/sphere.png

Projected gas mass in 10 concentric spherical shells around an observer in the L1_m8 simulation. The observer is at the centre of the sphere. The outer sphere has a comoving radius of approximately 2 Gpc. The full FLAMINGO outputs consist of 68 shells with a maximum comoving radius of 7.9 Gpc (\(z = 5\)).

Compton Y parameter at \(z < 0.05\)
../_images/comptony_z0.05.png

Mollweide projected full sky map of the thermal Sunyaev-Zel’dovich effect as quantified by the Compton y parameter for the redshift interval \(0 < z < 0.05\).

HEALPix maps of a range of physical quantities are available. For more information see the documentation links below and appendix A of Schaye et al (2023).