JWST uncovers a gas-shrouded supermassive black hole from the universe's first 700 million years

A JWST NIRSpec observation of the ultra-deep field source MoM-BH*-1, at a spectroscopic redshift of 7.756, reveals a spectrum dominated by an extreme Balmer break, broad Hβ emission with multiple peaks, and simultaneous Balmer-line absorption, all pointing to gas densities exceeding 10^9 cm⁻³. The authors model the system as a supermassive black hole of roughly 10^6-10^7 M⊙ embedded in a dust-free, turbulent gas envelope (n_H≈10^11 cm⁻³, N_H≈10^25.8 cm⁻²) that produces the observed red colours through gas opacity rather than dust extinction.

The point-source morphology (<117 pc) and tentative variability support an active accretion phase, possibly super-Eddington, consistent with theoretical pathways for early black-hole growth. The host galaxy is constrained to be a low-mass dwarf (M_*<10^8.5 M⊙) located about 60 kpc from a more massive companion, a configuration that may suppress molecular cooling and favor direct collapse. By combining the black-hole spectrum with a typical dwarf galaxy SED, the authors reproduce the characteristic V-shaped spectral energy distributions of the “little red dots” population, suggesting these enigmatic objects are powered by similar gas-enshrouded black holes. This discovery provides direct observational evidence for one of the proposed rapid-growth channels of the first supermassive black holes.