Source: ALMA finds cold gas in a quiescent z≈7.3 galaxy

Valentino et al., “Extended [CII] gas emission in and around a massive quiescent galaxy at z=7.3,” 19 June 2026 preprint. ALMA detects the [C II] 158-micron line from RUBIES-UDS-QG-z7 at z=7.27, an independent spectroscopic check of JWST’s redshift z≈7.29. Roughly 70% of the [C II] flux is extended around, rather than in, its tiny stellar core; the gas halo has effective radius 8±3 kpc, while the stellar effective radius is ~0.21 kpc.

Counterintuitive result: the authors infer substantial cold gas despite little recent star formation. Galaxy-scale molecular gas log10(Mmol/M☉)=9.53 (+0.32/−0.31) relies on a [C II]-to-gas conversion; the gas fraction is around 20% across most assumptions, ~10× lower than comparable star-forming galaxies. The gas detection is direct; the mass, origin and the proposed AGN-driven outflow are interpretations. Quenching by complete removal of all cold gas is disfavored; why this fuel makes so few stars remains the live question.

Test next: resolve gas kinematics and molecular gas more directly, and measure comparable objects over larger survey volumes. This is about galaxy formation and feedback, not by itself a proof against ΛCDM. See the topic brief.