Early universe articles from across Nature Portfolio

JWST detections of Si, C and Fe absorption lines in a bright z = 9.31 galaxy with a two-component clump structure suggest that mergers contributed to the rapid build-up of mass and chemical enrichment soon after the Big Bang.

Analysis of the JWST/NIRSpec spectrum of the recently observed Lyman-break galaxy JADES-GS+53.15508-27.80178 revealed a redshift of z = 7.3, a Balmer break and a complete absence of nebular emission lines, indicating that quenching occurred only 700 million years after the Big Bang.

An analysis of eight ultra-faint galaxies during the epoch of reionization with absolute magnitudes between −17 mag and −15  mag shows that most of the photons that reionized the Universe come from dwarf galaxies.

A black hole at the centre of a quasar at a redshift of z = 4 is accreting the mass of the Sun every day. The quasar’s extreme luminosity is equivalent to 50,000 times that of the Milky Way. Its broad-line region should be resolvable observationally and will provide an important test for broad-line region size–luminosity relationships.

JWST has revealed the most distant galaxies known, but photometric estimates of their redshifts are likely to be overly generous, owing to a statistical effect identified by Sir Arthur Eddington.

Through the past 12 billion years of cosmic time, galaxies have been in a near-equilibrium state, with their star-formation rates, stellar masses and chemical abundances tightly connected. But, from JWST observations, it now seems that at earlier times galaxies deviated from this relation, owing to the inflow of pristine gas in the early Universe.