Galaxy clusters are the largest gravitationally bound structures in the universe. Their enormous scale makes them the perfect environment to host cosmological phenomena that are otherwise not prominent. About 85% of the mass of a cluster is disguised in the form of dark matter, which does not interact with baryonic matter at all. Hence, gravitational lensing becomes a great tool to study the dark matter substructure within these clusters. This work is based on the LoVoCCS survey (Sheming Fu, Ian Dell'Antonio, et al), which aims to collect data from DECam and study the weak lensing signal in 107 clusters to examine the distribution of dark matter within them. We discovered that Abell 1285 has an unusually large lensing signal compared to its X-ray luminosity. A significant disagreement exists between the traditional X-ray mass estimates provided by various catalogs, such as the MCXC catalog (Piffaretti et al), and our weak lensing estimate. The focus of the thesis is to resolve this discrepancy. A multi-cluster analysis was carried out in different domains of the electromagnetic spectrum using methods like extracting the red sequence to estimate the luminosity, looking at the Sunyaev-Zeldovich effect, and studying the dispersion of redshifts in the field. We found that our estimates for optical luminosity across all clusters show an overall decreasing trend with a small peak around Abell 1285. While our estimates are in agreement with the X-ray catalogs, we found a major contamination in the field in the X-ray and millimeter regimes. This contamination might have affected the respective estimates, depending on how the subtraction was handled.
Shinde, Rahul,
"Investigating the Abnormal Weak Lensing Signal of Abell 1285"
(2023).
Physics Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://doi.org/10.26300/vxry-2y63
