Key Observations

• The James Webb Space Telescope (JWST) has detected nine sources of bright blue ultraviolet light
• The sources lie at a record distance: six at a redshift of z ≈17, and three at z ≈25
• This corresponds to a Universe of only 100-200 million years old after the Big Bang
• According to established cosmological models, neither stars nor galaxies should not have formed during this era.

The Scientific Problem

The detection of bright light from such an early epoch contradicts established models of galaxy formation.

At that time, the gas in the Universe should still have been too hot and would not have had time to cool and collapse under the influence of dark matter to form the first stars in such a short period (under 100-200 million years).

The observed objects appear to be too bright and, potentially, too massive for their time.

The Proposed Hypothesis

To explain the anomaly, astrophysicists (Andrea Ferrara et al.) have proposed the hypothesis involving primordial black holes (PBHs).

PBHs could have formed within the first seconds after the Big Bang from quantum fluctuations during the period of inflation.

By the age of 100-200 million years, these initially tiny (about the size of an atom) PBHs could have grown to around 10,000 solar masses by accreting surrounding gas.

The accreted gas heats to extreme temperatures and shines brightly, which could account for the observed ultraviolet radiation.

Thus, the earliest sources of light in the Universe might not have been stars, but actively accreting black holes.

Confirmation and Uncertainties

Confirmation required: The redshift of the candidates (z ≈17 and z ≈25) must be confirmed with spectroscopy.

Source sizes: JWST data show that around 30% of the candidates appear point-like (consistent with PBHs), while the remaining 70% are extended (more akin to galaxies).

Further implications: PBHs could have acted as the "seeds" for supermassive black holes found at the centres of early galaxies.

Alternative explanations: The objects could be data contaminants, or their existence may indicate the need to revise current evolutionary models.

Hypothesis verification: Studies of the cosmic microwave background (CMB) are required to search for potential signatures of PBHs.

Conclusion

JWST observations pose a serious challenge to our understanding of the "cosmic dawn." Either galaxies formed incredibly quickly (requiring a revision to current physics), or the first sources of light were primordial black holes. The answer will come from future spectroscopic observations and CMB analysis.