Full-sky Gravitational Lensing Simulation for Large-area Galaxy Surveys and Cosmic Microwave Background Experiments

5 Jun 2017  ·  Ryuichi Takahashi, Takashi Hamana, Masato Shirasaki, Toshiya Namikawa, Takahiro Nishimichi, Ken Osato, Kosei Shiroyama ·

We present 108 full-sky gravitational lensing simulation data sets generated by performing multiple-lens plane ray-tracing through high-resolution cosmological $N$-body simulations. The data sets include full-sky convergence and shear maps from redshifts $z=0.05$ to $5.3$ at intervals of $150 \, h^{-1}{\rm Mpc}$ comoving radial distance (corresponding to a redshift interval of $\Delta z \simeq 0.05$ at the nearby universe), enabling the construction of a mock shear catalog for an arbitrary source distribution up to $z=5.3$. The dark matter halos are identified from the same $N$-body simulations with enough mass resolution to resolve the host halos of the Sloan Digital Sky Survey (SDSS) CMASS and Luminous Red Galaxies (LRGs). Angular positions and redshifts of the halos are provided by a ray-tracing calculation, enabling the creation of a mock halo catalog to be used for galaxy-galaxy and cluster-galaxy lensing. The simulation also yields maps of gravitational lensing deflections for a source redshift at the last scattering surface, and we provide 108 realizations of lensed cosmic microwave background (CMB) maps in which the post-Born corrections caused by multiple light scattering are included. We present basic statistics of the simulation data, including the angular power spectra of cosmic shear, CMB temperature and polarization anisotropies, galaxy-galaxy lensing signals for halos, and their covariances. The angular power spectra of the cosmic shear and CMB anisotropies agree with theoretical predictions within $5\%$ up to $\ell = 3000$ (or at an angular scale $\theta > 0.5$ arcsin). The simulation data sets are generated primarily for the ongoing Subaru Hyper Suprime-Cam survey but are freely available for download at http://cosmo.phys.hirosaki-u.ac.jp/takahasi/allsky_raytracing.

PDF Abstract