Testing tidal alignment models for anisotropic correlations of halo ellipticities with Nbody simulations
Abstract
There is a growing interest of using the intrinsic alignment (IA) of galaxy images as a tool to extract cosmological information complimentary to galaxy clustering analysis. Recently, Okumura & Taruya derived useful formulas for the intrinsic ellipticityellipticity correlation, the gravitational shearintrinsic ellipticity correlation, and the velocityintrinsic ellipticity correlation functions based on the linear alignment (LA) model. In this paper, using largevolume Nbody simulations, we measure these alignment statistics for darkmatter haloes in real and redshift space and compare them to the LA and nonlinear alignment model predictions. We find that anisotropic features of baryon acoustic oscillations in the IA statistics can be accurately predicted by our models. The anisotropy due to redshiftspace distortions (RSDs) is also well described in the largescale limit. Our results indicate that one can extract the cosmological information encoded in the IA through the AlcockPaczynski and RSD effects.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 May 2020
 DOI:
 10.1093/mnras/staa718
 arXiv:
 arXiv:2001.05302
 Bibcode:
 2020MNRAS.494..694O
 Keywords:

 methods: statistical;
 galaxies: haloes;
 cosmological parameters;
 dark energy;
 largescale structure of Universe;
 cosmology: theory;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 Astrophysics  Astrophysics of Galaxies
 EPrint:
 9 pages, 6 figures