2025 Project Description

Investigating the Impact of Intrinsic Alignment on Optical Cluster Cosmology

Supervisors

Tomomi Sunayama
Find out more about supervisors on ASIAA website

Task Description and Goals

Galaxy clusters serve as powerful cosmological probes, yet their potential is hindered by systematic uncertainties such as projection effects in optical surveys. In 2019, we demonstrated that projection effects significantly bias cluster weak lensing measurements, posing a critical challenge to cluster cosmology. This study aims to explore an additional source of systematic bias by measuring the intrinsic alignment of member galaxies within clusters. If the observed intrinsic alignment is stronger than theoretical predictions, it could exacerbate projection-induced biases in cluster mass estimates and cosmological constraints. To address this, we will utilize N-body simulations to construct mock cluster catalogs, enabling a systematic investigation of the interplay between intrinsic alignment and projection effects. Our findings will provide essential insights into mitigating biases in future wide-field galaxy surveys.

Required Background

Strong programming skills and be proficient in Python, including experience with scientific computing libraries such as NumPy, SciPy, and Matplotlib. Familiarity with data analysis and simulations is preferred but not mandatory.