Probing Galaxy Cluster through Weak Lensing using Hyper Suprime-Cam Imaging Survey

This thesis work focuses on the methodology followed to estimate the masses of clusters through the study of the effects of weak gravitational lensing, detected by the Hyper Suprime-Cam survey. We compared the results for four clusters of different redshifts and the observed differences in the radial profile of each, using two different source selection methods: Color-Color cuts and P(z) cuts. We used data collected from the first year release (DR1) and its correspond- ing shape catalog (released for the wide-layer S16A data) for the purpose of estimating the tangential shear profile of the clusters. The clusters studied in this work are HSCJ021528-044041 at redshift 0.3323, HSCJ021322-060445 at redshift 0.6841, HSCJ021056-061154 at redshift 0.4340 and HSCJ020525-054356 at redshift 0.2896. We created a comprehensive compilation of the current methods used in lit- erature using data extracted from the data released by the Hyper-Suprime Cam survey, in particular in terms of galaxy selection within clusters, the selection of source galaxies and mass modeling according to Umetsu et al. [2020] For this work, we use the CLMM library to estimate the shear components of the ellipticity components available in the shape catalog, for both simulated data (generated galaxy clusters altering redshifts and masses) and real data (DR1 HSC) and compare results based on the redshift differences. We find that the higher the redshift the cluster is at, the lower the accuracy in the results for the mass obtained due to the difficulty in observing and scarcity of the source galaxies. We also conclude with the comparison of the two source selection methods that the Color-Color cut method rigorously rejects cluster and foreground galaxies but may reduce usable background galaxies, and the P(z) cuts method probabilistically selects background galaxies, potentially leading to larger sample sizes but higher contamination levels. Comparisons with literature show that mass estimates closer to reported values are achieved using the Color-Color cut method over the P(z) cut method.