With breakthroughs in astronomical observation, scientists have confirmed the presence of supermassive black holes at the centers of galaxies. The recent release of black hole images has increased people’s curiosity about black holes while providing more evidence to support Einstein’s theory of general relativity.
These supermassive black holes range in mass from millions to billions of solar masses. Amazingly, some of these black holes formed a billion years after the Big Bang. Understanding how these black holes formed and grew to such massive masses in such a short time has always been an important topic in modern astronomy.
A research team including Chi-Hong Lin and Ke-Jung Chen from the Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA) and Chong-Yuan Hwang from the Institute of Astronomy, National Central University have made significant new advances in the formation theory of supermassive black holes. Research results published The Astrophysical Journal.
The team used high-resolution simulations of galaxy mergers to investigate the growth of supermassive black holes and their effects on host galaxies. Introducing a new model of molecular clouds, they found that the growth of black holes occurs primarily through the accretion of molecular clouds during galaxy mergers.
Due to the dynamics of gravitational forces, massive molecular clouds can fall more efficiently to the galactic center compared to neutral and ionized gas, which rapidly increases the star formation rate of the galaxy and provides the necessary nutrients for the rapid growth of the black hole.
This allows black holes that were originally only a few million solar masses to grow to billions of solar masses within a few hundred million years, successfully explaining the observed properties of merging galaxies and their black holes.
“This research demonstrates a possible mechanism for the rapid growth of black holes and reveals the importance of molecular clouds in merging galaxies,” said Ke-Jung Chen.
“Our research results can give people a deeper understanding of galaxy evolution. We hope to have more observational results to confirm our conclusion,” said lead author Chi-Hong Lin.
Chi-Hong Lin et al., Rapid growth of galactic supermassive black holes by accretion of massive molecular clouds during major mergers of their host galaxies, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/acd841
Provided by Academia Sinica, Institute of Astronomy & Astrophysics