Speaker
Description
The rest-frame UV luminosity function (UV LF) and evolution thereof is a crucial component of understanding star formation in the early universe, and how star-forming galaxies contributed to cosmic reionization. Prior to JWST, the rate of decline of the UV LF at z > 8 was unclear, but early analyses of JWST data have suggested the presence of an unexpectedly large abundance of luminous galaxies at unexpectedly high redshifts, potentially pointing to previously unknown factors governing early star formation (e.g. an evolving star formation efficiency, a top-heavy stellar initial mass function, stochastic star formation histories, etc.). In this talk, I will present the UV LF at z~9-15 derived from ~250 galaxies identified over the full 125 square arcminutes of JADES imaging, providing a view of the redshift evolution of the UV LF and cosmic UV luminosity density down to M_UV~-16.5 over ~300 million years of cosmic time. I will first discuss implications for early star formation of the UV LF evolution found in the JADES fields. Then, I will consider implications of the z~9-15 UV luminosity density for the reionization timeline and early growth of ionized bubbles, especially in the context of the possible existence of large, pMpc-scale ionized bubbles as early as z~9.
