Oral Presentation

Cosmological simulations of the first galaxy formation and comparisons with JWST data

Author(s): Hidenobu Yajima (U. of Tsukuba), Makito Abe (U. of Tsukuba), Hajime Fukushima (U. of Tsukuba), Yoshiaki Ono (U. of Tokyo), Yuichi Harikane (U. of Tokyo), Masami Ouchi (NAOJ), Takuya Hashimoto (U. of Tsukuba), Sadegh Khochfar (U. of Edinburgh)

Presenter: Hidenobu Yajima (University of Tsukuba)

We study the formation of the first galaxies in overdense regions modelled by our new simulation project FOREVER22. Our simulations successfully reproduce the star formation rates and the relations between UV brightness and stellar mass of candidate galaxies at z=10−14 observed by James Webb Space Telescope (JWST). We find that the first galaxies host population III stars of which the UV radiation contributes to the observed fluxes. The mass fraction of population III stars decreases as the stellar mass increases. We suggest that population III-dominated galaxies can be detected if future telescopes will be able to observe dwarf galaxies with stellar masses of 10^5 Msun at redshifts greater than 10.