On November 14, 2024, an article published in Nature Astronomy by Françoise Combes from the Paris Observatory and Benjamin L'Huillier from Sejong University presents findings indicating a connection between the vicinity of black holes and their host galaxies. The study reveals that jets emitted by black holes align with the structure of their galaxies.
Recent analyses of radio telescope data suggest that the shapes of galaxies correlate with the black holes they harbor. Black holes are typically categorized as either stellar mass or supermassive. Stellar black holes are comparable in mass to the Sun, while supermassive black holes can be a million times more massive.
Despite their mass, supermassive black holes represent less than 1% of the total stellar mass of their galaxies and are significantly smaller than their host galaxies, often by a million times in radius.
The study emphasizes that supermassive black holes are relatively rare, with our Milky Way housing one, Sagittarius A*, at its center. Most galaxies also contain a supermassive black hole, which can become active as dust and gas are drawn in by its gravitational pull.
The research utilized Very Long Baseline Interferometry (VLBI), a technique that enhances resolution beyond that of individual telescopes, allowing astronomers to observe jets from black holes up to a few light-years from their origin. This method provides insights into the orientation of the accretion disk and potentially the properties of the black hole itself.
Furthermore, the study compared the direction of quasar jets with the axes of their host galaxies, finding a significant connection. This correlation is unexpected given the vast difference in scale between the small size of black holes and the extensive dimensions of galaxies, which can span hundreds of thousands of light-years.
The implications of this research may inform our understanding of galaxy formation, particularly in how spiral galaxies interact and evolve into elliptical ones. The findings also relate to recent observations from the James Webb Space Telescope, which identified massive quasars forming earlier in the universe than previously thought, suggesting a need to reassess theories regarding galaxy formation and the role of black holes.