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The onset of star formation 250 million years after the Big Bang

2018; Nature Portfolio; Volume: 557; Issue: 7705 Linguagem: Inglês

10.1038/s41586-018-0117-z

1476-4687

Takuya Hashimoto, Nicolas Laporte, Ken Mawatari, Richard S. Ellis, Akio Inoue, Erik Zackrisson, Guido Roberts-Borsani, Wei Zheng, Yoichi Tamura, F. E. Bauer, Thomas J. Fletcher, Yuichi Harikane, Bunyo Hatsukade, Natsuki H. Hayatsu, Yuichi Matsuda, Hiroshi Matsuo, Takashi Okamoto, Masami Ouchi, R. Pelló, Claes-Erik Rydberg, Ikkoh Shimizu, Yoshiaki Taniguchi, Hideki Umehata, Naoki Yoshida,

Stellar, planetary, and galactic studies

A fundamental quest of modern astronomy is to locate the earliest galaxies and study how they influenced the intergalactic medium a few hundred million years after the Big Bang1–3. The abundance of star-forming galaxies is known to decline4,5 from redshifts of about 6 to 10, but a key question is the extent of star formation at even earlier times, corresponding to the period when the first galaxies might have emerged. Here we report spectroscopic observations of MACS1149-JD16, a gravitationally lensed galaxy observed when the Universe was less than four per cent of its present age. We detect an emission line of doubly ionized oxygen at a redshift of 9.1096 ± 0.0006, with an uncertainty of one standard deviation. This precisely determined redshift indicates that the red rest-frame optical colour arises from a dominant stellar component that formed about 250 million years after the Big Bang, corresponding to a redshift of about 15. Our results indicate that it may be possible to detect such early episodes of star formation in similar galaxies with future telescopes. Observation of the emission line of doubly ionized oxygen at a redshift of 9.1096 reveals that star formation began at a redshift of about 15, around 250 million years after the Big Bang.