Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne, Victoria, Australia.
Department of Astronomy, Yale University, New Haven, CT, USA.
Nature. 2023 Apr;616(7956):266-269. doi: 10.1038/s41586-023-05786-2. Epub 2023 Feb 22.
Galaxies with stellar masses as high as roughly 10 solar masses have been identified out to redshifts z of roughly 6, around 1 billion years after the Big Bang. It has been difficult to find massive galaxies at even earlier times, as the Balmer break region, which is needed for accurate mass estimates, is redshifted to wavelengths beyond 2.5 μm. Here we make use of the 1-5 μm coverage of the James Webb Space Telescope early release observations to search for intrinsically red galaxies in the first roughly 750 million years of cosmic history. In the survey area, we find six candidate massive galaxies (stellar mass more than 10 solar masses) at 7.4 ≤ z ≤ 9.1, 500-700 Myr after the Big Bang, including one galaxy with a possible stellar mass of roughly 10 solar masses. If verified with spectroscopy, the stellar mass density in massive galaxies would be much higher than anticipated from previous studies on the basis of rest-frame ultraviolet-selected samples.
天文学家已经在红移约 6 的位置发现了恒星质量高达约 10 个太阳质量的星系，这大约是大爆炸后 10 亿年的时间。在更早的时期，由于需要用于准确质量估计的巴尔末消光区被红移到了 2.5μm 以上的波长，因此很难找到大质量星系。在这里，我们利用詹姆斯·韦伯太空望远镜的早期释放观测数据的 1-5μm 覆盖范围，来寻找宇宙历史最初约 7.5 亿年内本质上是红色的星系。在调查区域，我们在 7.4≤z≤9.1 的范围内发现了六个候选的大质量星系（恒星质量超过 10 个太阳质量），这是大爆炸后 500-700Myr 的星系，其中一个星系的恒星质量可能约为 10 个太阳质量。如果通过光谱学得到证实，那么大质量星系的恒星质量密度将远远高于之前基于紫外波段选择样本的研究预期。
