Verifications of Scaling Relations Useful for the Intrinsic Alignment Self-calibration

The galaxy intrinsic alignment (IA) is a major challenge of weak lensing cosmology. To alleviate this problem, Zhang proposed a self-calibration method, independent of IA modeling. This proposal relies on several scaling relations between two-point clustering of IA and matter/galaxy fields, which were previously only tested with analytical IA models. In this paper, these relations are tested comprehensively with an N-body simulation of 3072³ simulation particles and boxsize 600h ^-1 Mpc. They are verified at the accuracy level of { \mathcal O }(1) % over angular scales and source redshifts of interest. We further confirm that these scaling relations are generic, insensitive to halo mass, weighting in defining halo ellipticities, photo-z error, and misalignment between galaxy ellipticities and halo ellipticities. We also present and verify three new scaling relations on the B-mode IA. These results consolidate and complete the theory side of the proposed self-calibration technique.