Towards the First HSC-SSP Cluster Cosmology Results: Focus on Robustness against Projection Effects

2022 Fiscal Year Annual Research Report

• Project/Area Number: 21K13917
• Research Institution: The University of Tokyo
• Principal Investigator: PARK YOUNGSOO 東京大学, カブリ数物連携宇宙研究機構, 特任研究員 (20835467)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: Cosmology / galaxy clusters / weak lensing / large scale structure

Outline of Annual Research Achievements

In FY2022 (May 2022 to September 2022), I have carried out follow-up research related to the results obtained inFY2021. Specifically, my collaborators and I have obtained a new cluster lensing measurement from the HSC-SSPfirst-year data. I have then performed preliminary comparisons between the FY2021 results, using SDSS shapemeasurements, and new results using the HSC-SSP shape measurements. Preliminary results suggest that thepuzzles from FY2021 may be solved with the new cluster lensing measurements, and further studies and analysesare ongoing today.
I have also refactored the codebase for the cluster cosmology analysis pipeline and have shared it with mycollaborators as a private github repository. This refactoring has made it easy for current and future researchersinterested in contributing to quickly learn and become able to perform the analysis, in particular the running of MarkovChain Monte Carlo simulations for likelihood analyses.
Both of the above achievements will allow the impact of this grant to last long after its end.