English

Verifications of scaling relations useful for the intrinsic alignment self-calibration

Cosmology and Nongalactic Astrophysics 2018-09-05 v2 Astrophysics of Galaxies

Abstract

The galaxy intrinsic alignment (IA) is a major challenge of weak lensing cosmology. To alleviate this problem, Zhang (2010, MNRAS, 406, L95) 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 NN-body simulation of 307233072^3 simulation particles and boxsize 600 h1Mpch^{-1} \, \mathrm{Mpc}. They are verified at the accuracy level of O(1)%\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-zz 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.

Keywords

Cite

@article{arxiv.1805.03672,
  title  = {Verifications of scaling relations useful for the intrinsic alignment self-calibration},
  author = {Xian-guang Meng and Yu Yu and Pengjie Zhang and Yipeng Jing},
  journal= {arXiv preprint arXiv:1805.03672},
  year   = {2018}
}

Comments

6 pages, 7 figures, published in ApJ