Measuring mass and structure of the Universe with LSST: importance of precise photometric redshift estimation and CCD sensor effects

Sensor anomalies and photometric redshift are the main areas studied to find and correct the error in measurement of the cosmological parameters more precisely and more accurately. For this purpose, we have tested and analyzed over 200 CCD sensors used for Large Synoptic Survey Telescope (LSST) production at Brookhaven National Laboratory. Using those data, we have studied Tree Rings and Charge Transfer Efficiency. These two sensor effects were studied to correct shape distortion of the light sources due to the CCD, from the shear measurement for Weak Lensing research. We have developed a new method to study the blending effects in simulated data prepared for Data Challenge of Dark Energy Science Collaboration (DESC). We used it to systematically study the impact of blending on photometric redshift estimation. From observations we know that ordinary matter consist of 5 % of the Universe and the rest is dark matter and dark energy. The LSST is proposed to study dark matter and dark energy, collaborating with DESC. With improved understanding of blending effects and effective corrections of instrumental effects, we are one step closer to measure properties of dark energy and dark matter. More accurate and precise measurement of the cosmological parameters will support the survey to understand how the Universe has been formed and transformed over time.