An analysis of the spectrum of the distant galaxy ADFS-KMTDOG-102, previously studied using the Gemini South telescope, has revealed that the so-called "Little Red Dots" (LRDs)—tiny, dust-shrouded galaxies—may be the precursors of Blue Dust-Obscured Galaxies (BlueDOGs) that emerged during the era known as "cosmic noon."

Origin and Characteristics of LRDs

The "Little Red Dots" appeared within the first billion years after the Big Bang. These compact objects, found in various regions of the Universe, are believed to be linked to processes typical of the early stages of cosmic evolution. Earlier, by examining the structure of LRDs with the James Webb Space Telescope, astronomers suggested that they might represent the initial phases in the formation of supermassive black holes, though their true nature remains unclear.

Blue Dust-Obscured Galaxies

Unlike LRDs, Blue Dust-Obscured Galaxies emerged 2–3 billion years after the Big Bang. Their most distinctive feature is a sudden surge in ultraviolet emission. Astronomers attribute the nature of BlueDOGs either to intense star formation or to extraordinary activity in the galactic nucleus.

The Connection Between LRDs and BlueDOGs

To trace the evolution of these galaxies, researchers from the Institute of Astronomy and Space Sciences, together with colleagues from the University of Science and Technology (both institutions located in South Korea), proposed the hypothesis that "Little Red Dots" and Blue Dust-Obscured Galaxies represent different stages in the development of the same class of objects.

Studying the Galaxy ADFS-KMTDOG-102

Astronomers focused on the luminous galaxy ADFS-KMTDOG-102, previously observed with Gemini South. Its mass is estimated to exceed two trillion solar masses, while the central black hole is more than 10 billion times the mass of the Sun. About 95% of the galaxy’s luminosity is attributed to the activity of its nucleus, despite a dense veil of dust.

Spectral analysis showed that over the past 10 million years, new stars in this galaxy have formed six times faster than in the previous 100 million years. The high abundance of heavy elements—dozens of times greater than that of the Sun—points to a turbulent history of chemical enrichment.

Evolutionary Link and Research Prospects

Since the spectral energy distribution in ADFS-KMTDOG-102 almost completely matches the characteristics of LRDs, researchers have suggested that LRDs and BlueDOGs may be different evolutionary stages of the same class of objects, separated by billions of years of cosmic evolution.

This connection opens up unique opportunities for further research: "Little Red Dots" can only be detected with the James Webb Space Telescope, while Blue Dust-Obscured Galaxies are observed using other instruments. The results of this scientific work have been published on the Cornell University preprint server.

If the hypothesis is confirmed, astronomers in the future will be able to trace the life cycle of galaxies from the first billion years of the Universe to the era of "cosmic noon." However, the current data should be interpreted with caution, as it may not represent a single evolutionary path, but rather different stages in the growth of massive galaxies.