Red Dots Are Not Twins of Dusty Quasars ⚡ экспресс
«Little Red Dots» (LRDs) are compact dusty galaxies with a V-shaped spectral energy distribution from the ultraviolet to the near-infrared, discovered by JWST with unexpectedly high number densities. They qualitatively resemble «blue-excess hot dusty galaxies» (BHDs)—a population of hyper-luminous dust-enshrouded quasars at z~1–4, accreting near the Eddington limit. Multi-wavelength comparison revealed that these are distinct populations: the V-shape appears at longer wavelengths in BHDs due to different selection methods, indicating significantly lower dust obscuration in LRDs. The bluer infrared continuum colors of LRDs suggest an absence of hot dust heated by active nucleus accretion, and the blue excess is unlikely to be explained by scattered AGN light. Compact morphology and low X-ray detection frequency point to a different formation pathway than BHDs, which are thought to arise from super-Eddington accretion following major galaxy mergers.
At first, they were mistaken for rare 'furnace' galaxies, where a black hole runs at full throttle, heating dust until it glows. Both types show a V-shaped dip in their spectrum—dust muffles some colors while letting others through. But precise brightness measurements revealed a difference. In the 'furnaces,' the dust is so hot that radiation spills deep into the red and bursts out as X-rays. In the red dots, the dust is cooler, and there's almost no X-rays.
It seems their 'engines' never experienced violent flares after galaxy collisions and grew gradually. This hunch changes the picture of how galaxies matured after the Big Bang.
🎯 The first Webb images were so thick with these dots that astronomers jokingly called them 'polluters' of galactic surveys.