Rosella: A mock catalogue from the P-Millennium simulation

Understand

The scientific exploitation of the Dark Energy Spectroscopic Instrument Bright Galaxy Survey (DESI BGS) data requires the construction of mocks with galaxy population properties closely mimicking those of the actual DESI BGS targets.

• We create a high fidelity mock galaxy catalogue, including information about galaxies and their host dark matter subhaloes.
• The mock catalogue uses subhalo abundance matching (SHAM) with scatter to populate the P-Millennium N-body simulation with galaxies at the median BGS redshift of ~ 0.2, using formation redshift information to assign (g-r) rest-frame colours.
• The mock provides information about r-band absolute magnitudes, (g-r) rest-frame colours, 3D positions and velocities of a complete sample of DESI BGS galaxies in a volume of (542 Mpc/h)^3, as well as the masses of host dark matter haloes.