Introducing the GION Lightcone Simulation Suite for Multi-Wavelength Large-Scale Structure Cosmology

Abstract

We present the GION (Ginkaku Lightcone Multi-wavelength Simulation Project) simulation suite: 10 full-sky high-resolution cosmological lightcone simulations and their associated products for multi-wavelength large-scale structure cosmology. We use the TreePM $N$-body code GINKAKU, which is highly optimized in the massively parallel environment, and integrate the on-the-fly lightcone construction technique. Each lightcone simulation is run with $6144^3$ particles in a volume of $(1.5 \, h^{-1} \, \mathrm{Gpc})^3$, which corresponds to a particle mass of $1.28 \times 10^9 \, h^{-1} \, \mathrm{M}_\odot$, and extends to $z = 5$. The fine mass resolution and the depth of the lightcone simulations allow us to resolve dark matter halos down to $10^{11} \, h^{-1} \, \mathrm{M}_\odot$ in the high-redshift Universe, which is crucial for applications to the Stage-IV cosmological surveys. The fundamental statistics of the simulations, including the matter power spectrum, halo power spectrum, and halo mass function, are validated against theoretical predictions. We also generate various large-scale structure observables from the lightcone outputs: the dark matter halo catalogs, mock galaxy samples, weak lensing convergence maps, and thermal and kinematic Sunyaev-Zel'dovich (tSZ and kSZ) maps. The angular power spectra of these observables, including the cross-correlation between weak lensing and the tSZ effect, are in good agreement with theoretical predictions, demonstrating that the suite provides mutually consistent multi-wavelength observables on the same lightcone. The GION simulation suite will be publicly available and can be used for various cosmological analyses to address the observational systematic effects and validate theoretical models.