Scientists have discovered black holes at maximum settings – today there are no such things

A year ago, the James Webb Space Telescope discovered new objects in the early universe called Little Red Dots (LRDs). To the observatory’s sensors, they literally looked like dots with an extremely large red shift. Since then, scientists have put forward a number of hypotheses about the nature of these objects, which allows them to find an explanation for their origin. The new work sheds more light on this mystery of the early universe.

Image source: AI generation Grok 3/3DNews

The first and largely correct assumption was that the “little red dots” were active galactic nuclei (quasars). The peculiarity of the LRD was that, unlike quasars, they emitted very weakly in the radio range and X-ray spectrum. Supermassive black holes located inside distant galaxies do not behave this way – they literally glow in the X-ray range.

One of the things scientists quickly learned about these objects is that their spectra are greatly broadened by the Doppler effect, indicating that the gas emitting the light is rotating around the central region at a tremendous speed of more than 1,000 kilometers per second.

To study the “little red dots” in more detail, the scientists used Webb’s instruments to collect high-resolution spectra for 12 such objects. The data were then compared with models of supermassive black holes. The analysis showed that everything could be happening inside a young galactic cloud. An accretion disk surrounding a black hole should be rotating inside the galaxy at a very high speed. At the same time, the galactic cloud should be highly ionized. In this case, the dense cloud of free electrons surrounding the galaxy would indeed absorb most of the X-ray and radio emission.

On the other hand, for LRDs to reach the observed luminosity in the infrared range, the black hole’s radiation power must be at its maximum level. Observations show that this power is close to the Eddington limit, after which the black hole would simply accelerate the matter around itself and the galaxy with its “light”, including ionized gas masking X-ray and radio emission.

Some of the open galaxies of “small red points”. Image source: NASA

All this suggests that the “little red dots” are very young supermassive black holes that are rapidly growing and reaching maturity. This is supported by estimates of their mass, which range from 10,000 to 1,000,000 solar masses, much smaller than typical supermassive black holes. This model also helps explain why we do not see closer, lower-redshift LRDs. In the course of their violent evolution, operating at the limit of their power, they quickly disperse the ionized cloud surrounding them and turn into typical quasars, which are abundant in the Universe and to which scientists have long been accustomed.