Abstract

How did galaxies start forming stars? What are the conditions in typical low-mass, star-forming galaxies at z_{8 and above? Recent observations with JWST indicate several critical puzzles in studies that address these questions. Chief among these, galaxies started forming stars early and possibly at an extraordinary rate and in more compact clumps than previously thought. I will present the latest results from the JWST Bullet Cluster observations, which we will use to measure the properties of dark matter. I will also show the discovery of a highly magnified z=11 lensed arc. The intrinsic luminosity of the galaxy is 0.05L*, making it the lowest luminosity spectroscopically confirmed galaxy at z>10 discovered to date. The galaxy contains three star-forming components with sizes of 10 remarkably compact globular-cluster-like clumps and spectroscopically confirmed Little Red Dots with strong AGN signatures. All these results allow the detailed studies of star formation at sub-10pc scales at the epoch of reionisation.}