研究成果・発表論文

FOREVER22: The first bright galaxies with population III stars at redshifts z 10-20 and comparisons with JWST data

Yajima, Hidenobu,   Abe, Makito,   Fukushima, Hajime,   Ono, Yoshiaki,   Harikane, Yuichi,   Ouchi, Masami,   Hashimoto, Takuya,   & Khochfar, Sadegh


要旨

We study the formation of the first galaxies in overdense regions modelled by the FOREVER22 simulation project. Our simulations successfully reproduce the star formation rates and the MUV - Mstar relations of candidate galaxies at z ~ 10 - 14 observed by James Webb Space Telescope (JWST). We suggest that the observed galaxies are hosted by dark-matter haloes with Mh 1010 Mandareinshort- periodstarburstphases.Ontheotherhand,evensimulatedmassivegalaxiesinoverdenseregionscannotreproducetheintensestarformationratesandthelargestellarmassesofobservedcandidatesatz~ 16. Also, we show that the contribution of population III stars to the UV flux decreases as the stellar mass increases and it is a few per cent for galaxies with Mstar ~ 107 M.Therefore,apartoftheobservedfluxbyJWSTcouldbethelightfrompopulationIIIstars.OursimulationssuggestthattheUVfluxcanbedominatedbypopulationIIIstarsandtheUV- slopeshowsβ -3 if future observations would reach galaxies with Mstars ~ 105 Matz~ 20 of which the mass fraction of population III stars can be greater than 10 per cent.




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