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Seminar
Gravitational Flexion Measurement in Weak Lensing and JWST Applications

Abstract

High-precision data obtained by new-generation observational instruments such as JWST and EUCLID are expected to bring new developments to dark energy research. As these datasets surpass conventional data both in quantity and quality, there arises a need for more accurate analytical methods. Weak gravitational lensing stands out as a valuable tool for probing dark matter and dark energy. Traditionally, gravitational shear, a combination of the second derivative of the lens potential, has been measured to reconstruct mass distribution. However high-quality space imaging data are expected to contain more detailed information of the lensing potential. We have developed a new method to measure the gravitational flexion, which corresponds to certain combinations of the third derivatives of the lens potential. Measuring flexion enables a more accurate mass reconstruction. In this talk, I will introduce our method of measuring flexion and present the results of flexion measurement for the JWST cluster SMACS0723.3-7327.