work First Stellar cluster formation at z = 15 - 25 Origins of luminous UV emissions from the first galaxies at z = 15 - 10 Modeling of HII regions and chemical evolution using FirstLight simulations Morphologies of high-redshift galaxies using FirstLight simulations Origins of [OIII]/[CII] Ratios: Ionized and Neutral ISM Physics Using a sub-pc resolution radiative transfer simulations collaboration Contribution to Observation The Supersonic Project Collaboration with UCLA group