Overview
- JWST’s NIRCam has revealed tiny red sources with bright cores and diffuse halos concentrated in the very early universe.
- Analyses indicate the population becomes common roughly 600 million years after the Big Bang and declines by about 1.5 billion years.
- Observations present contradictions, including energetic appearance alongside unexpectedly weak X-ray emission.
- Additional diagnostics point to very dense gas and, in some cases, ionized iron lines and irregular brightness across wavelengths.
- Teams are organizing deeper JWST spectroscopic campaigns and coordinating ground- and space-based follow-ups to determine their nature.