Affiliation: National Astronomical Observatory of Japan – Univ. of Tokyo

Contribution: Invited

Title: Focus on: Early Galaxy Formation

Abstract: Over the decades, astronomers have discussed how stars form in the first galaxies at very high redshifts. For examples, massive stars may be selectively produced due to missing coolants of metals, which may cause characteristic supernovae including pair-instability supernovae or create seed black holes for supermassive black holes via a direct collapse. Globular clusters would form through a physical mechanism that is very different from present-day star formation. These open questions are now actively addressed by observational studies exploiting the great capabilities of JWST. Here I present recent observational progress in studies of early galaxy formation at z~10 uncovered using various JWST photometric and spectroscopic data supplemented with the ground-based observational data, and discuss physical properties of early galaxies including elemental abundances and galactic dynamics for understanding early star formation, supernova explosions, and galactic nucleus activity. Finally, I introduce ongoing efforts to explore the important epoch of cosmic reionization through the combination of JWST and Subaru large-area massive spectroscopy for the ionization states of the inter-galactic medium together with the forthcoming 21cm observations.

This contribution can be found here (pdf).