Ages of Candidate Cosmic Ancients

Maisie’s Galaxy and CEERS-93316 shown at six infrared wavelengths, with small circles highlighting each object. The galaxies are seen clearly in the images at longer wavelengths (right), but at shorter wavelengths (left) the galaxies ‘drop out’ and disappear. The spectrum of Maisie’s Galaxy shows a distinctive sharp ‘cutoff’ at a particular wavelength known as Lyman alpha (Ly 𝛼), confirming that this galaxy was observed only 390 million years after the Big Bang, while the spectrum of CEERS-93316 fades gradually from right to left and presents oxygen (O), hydrogen (H) and sulfur (S) emission, indicating that it comes from the ‘adolescent universe’, 1.2 billion years after the Big Bang.