A Flashlight Wrapped in Red Tape: Why Active Cores Change Color ⚡ экспресс
A flashlight wrapped with red tape on its sides shines white straight ahead and reddish from the side. Active galactic nuclei work the same way: at the center, a supermassive black hole is surrounded by a disk of hot gas and cosmic dust. Dust accumulates in the plane of the disk. Looking from above, we see a bright blue glow. Looking from the edge, the dust obscures the center, letting through only reddish light. The same object can appear as a "blue dot" or a "red dot".
The James Webb Space Telescope has spotted many such dots in the early Universe. Analysis of their light (spectroscopy) revealed an unusually bright hydrogen line. A new model reproduced these spectra and showed that the cause is the viewing angle. It’s remarkable that the dust around the black hole is no more than in a small cloud, yet it completely changes the color of the core.
This discovery refines our understanding of how supermassive black holes grew in young galaxies. There are fewer "red" and "blue" dots than we thought—they are the same objects seen from different angles. Now astronomers can find hidden black holes and estimate the amount of cosmic dust.
🎯 There is no more dust around a supermassive black hole than in a small cloud, but it’s enough to completely change the color of the entire nucleus.