Poster Presentation
Weak Lensing Measurement of Nearby, X-ray Luminous Galaxy Clusters with Subaru Hyper Suprime-Cam
Presenter: Fuyuko Tanaka (Nagoya University)
Density fluctuations in the early universe evolved under the competition between gravitational interactions due to dark matter and accelerated expansion caused by dark energy. As a consequence, large-scale structure, or the so-called cosmic web, which consists of galaxy clusters/groups, filaments, and voids, is formed. Galaxy clusters are the most massive objects in the universe, composed mainly of hot gas and dark matter. Their total mass can be measured using "weak gravitational lensing", whereby the gravity of a foreground galaxy cluster bends the light from background galaxies. The cluster mass function, which represents the number density of galaxy clusters as a function of mass, is sensitive to cosmological parameters, such as the matter energy density Ωm and the amplitude of matter density fluctuations σ₈. Galaxy clusters are generally detected using X-ray luminosity, Sunyaev-Zel’dovich signals, and the spatial concentration of galaxies. Establishing a relationship between mass and these observables is essential to linking the mass function with these observational quantities. In this study, I use a cluster sample from the Local Volume Complete Cluster Survey (LoVoCCS), which focuses on nearby (0.03 10⁴⁴ erg/s) galaxy clusters. One of the primary science goals of LoVoCCS is to establish a precise mass-X-ray luminosity relationship. As a first step, I estimated the masses of 19 galaxy clusters, a northern portion of LoVoCCS clusters observed by the Subaru Telescope's Hyper Suprime-Cam (HSC), using weak gravitational lensing. I present the current results of this study.
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