| 研究実績の概要 |
The main goal of the project was to explore halo assembly bias and the edges of galaxy clusters in observations - called the splashback radius of the galaxy clusters. I have explored systematics with optical galaxy cluster detections after some of the reports of such systematics present in real galaxy cluster catalogs. Since no credible mock galaxy cluster catalogs existed to investigate this, I have worked on making such mock catalogs possible. I have found that due to optical cluster finding systematics, it is quite difficult to establish the presence of halo assembly bias in observations, and such systematics could also plague the inferred locations of the splashback radius. In FY 2017, I have further explored the detection of splashback radius using galaxy cluster samples detected using Xrays (ROSAT) or in the Sunyaev Zeldovich effect (Planck) instead of using the optically selected galaxy clusters. We made use of the PanStarrs galaxy catalog to perform galaxy cluster-galaxy cross-correlations. We have detected the splashback radius of galaxy clusters even when using this sample. We are in the process of comparison of these detected splashback radius with the expectation from cosmological simulations. In FY 2017, I have also worked on the Hyper Suprime Cam Survey weak lensing analysis. I have worked on establishing a pipeline to compute the galaxy galaxy weak lensing signal, to compute covariances for the measurements using mock galaxy catalogs, and establishing systematic requirements for galaxy shear catalogs, as well as estimating photometric redshift biases.
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