Abstract
Optical and near-infrared transients discovered by the Hubble Space Telescope (HST) and the James Webb Space Telescope (JWST) behind galaxy cluster lenses include extremely magnified stars at redshift z > 1 and multiply imaged supernovae (SNe). The detection of lensed stars and other microlensed sources behind galaxy clusters is scientifically important not only because it extends our viewing distance of individual stars that depict an earlier stage of galaxy evolution compared to our nearby galaxies, but also because it provides a unique probe of the dark microlenses and small-scale dark matter halos and subhalos in the clusters. On the other hand, strong-lensed SNe are especially valuable, because the lens magnification allows us to detect SNe at high redshifts, and the relative time delays of a multiply imaged SN enable us to study its evolution and to estimate the cosmic expansion rate. In this talk, I will describe recent discoveries of these two types of gravitationally lensed transient phenomena. I will talk about the computer-vision techniques we designed for our future multi-messenger observations and the application of these methods in the existing HST and JWST data.
Anyone interested is welcome to attend.