- July 17, 2023, 2:00 pm US/Central
- Curia II
- Ben Zhang, U. Chicago
- Host: Dylan Temples, dtemples@fnal.gov
Abstract: Galaxy cluster abundance is one of the pillars of modern cosmology, with weak-lensing the gold standard for cluster mass calibration. Despite this achievement in modern cosmology, uncertainties and systematics in cluster observables hampers this probe in cosmological studies. With the aim of achieving percent-level cluster mass estimation, I present the modeling of two systematics — triaxiality bias and the correlated scatter of weak lensing observables — using a set of N-body simulations with different galaxy-halo connection models. In our first project, we find that triaxiality can be forward modeled as a boosting in the observed cluster richness and the weak lensing signal when clusters have their major axes oriented toward the line of sight. In the second project, we provide for the first time a model for the intrinsic correlated scatter between weak lensing signal and cluster richness and find a negative correlation between lensing signal and galaxy number count at small scales which can be quantitatively accounted for by the halo formation history. These results provide both qualitative physical understanding of these systematics and quantitative templates for modeling them in cluster abundance analyses.