Ten billion years ago, the universe was speckled with strange crimson sparks. The JWST spotted them in images at distant redshifts — compact sources blazing like entire galaxies yet no larger than a tiny central region. Astronomers nicknamed them “little red dots.” Their nature long defied explanation.

The key turned up in the classic theory of accretion disks by Nikolai Shakura and Rashid Alievich Sunyaev. When too much gas falls onto a black hole, it cannot swallow it all. The system enters a supercritical accretion state — a cosmic pressure cooker. Excess matter is flung away as a dense, optically thick wind. This gaseous shroud heats to thousands of kelvins and glows red, masking the hole. That’s how a red dot is born.

The model hinges on just two parameters — black hole mass and the dimensionless accretion rate. The photospheric temperature (the surface where light escapes) drops as both increase. For typical values, it lies in the range 3000–6000 K — exactly the red hues expected from LRDs. The luminosity nearly reaches the limit set by Arthur Eddington and scales linearly with mass. Meanwhile, spectroscopy completes the picture: the plasma wind, flying outward at about 1000 km/s, broadens hydrogen lines via Thomson scattering off electrons. The Balmer jump and decrement, calculated for a partially ionized gas, match those measured in many LRDs.

The cosmic pressure cooker rewrites the growth story of the first galaxies. In the young universe, black holes probably spent long stretches in supercritical mode, pumping far more energy into space than they stored as mass. This explains why the active galactic nuclei of that era look different from their quiet descendants. Future numerical simulations that include magnetic fields and metallicity (the chemical composition of the gas) will refine how transparent such a cooker can be and how long it can “vent steam” without tearing its host galaxy apart.

Data from JWST keep pouring in, and soon astronomers will have spectra for thousands of dots. Behind the red glow may lie not only the hunger of black holes but the very mechanism that lit up the first quasars. Ten billion years later, their light still reaches us — the crimson afterglow of distant cookers.