HYMALAIA: a hybrid lagrangian model for intrinsic alignments
Abstract
The intrinsic alignment of galaxies is an important ingredient for modelling weak-lensing measurements, and a potentially valuable cosmological and astrophysical signal. In this paper, we present HYbrid Model Advected from LAgrangian space for IA (HYMALAIA): a new model to predict the intrinsic alignments of biased tracers. HYMALAIA is based on a perturbative expansion of the statistics of the Lagrangian shapes of objects, which is then advected to Eulerian space using the fully non-linear displacement field obtained from N-body simulations. We demonstrate that HYMALAIA is capable of consistently describing monopole and quadrupole of halo shape-shape and matter-shape correlators, and that, without increasing the number of free parameters, it does so more accurately than other perturbatively inspired models such as the non-linear alignment model and the tidal-alignment-tidal-torquing model.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2024
- DOI:
- 10.1093/mnras/stae1331
- arXiv:
- arXiv:2307.13754
- Bibcode:
- 2024MNRAS.531.2684M
- Keywords:
-
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 17 pages, 9 figures. Accepted version published in MNRAS