Supermassive black holes alter the chemical evolution of galaxiesaccording to a study in which the Astrophysical Institute of Andalusia, dependent on the Higher Council for Scientific Research (IAA-CSIC).
This study shows how the activity of a supermassive black hole, hidden in the heart of a quasar, has transformed the chemical composition of the gas in the galaxy. Quasars are one of the most luminous objects that can be observed in the universe. Like other active galaxies, they have a supermassive black hole at their center.
Black hole’s intense gravity generates extreme temperatures and pressures in the accretion disk, which causes the emission of intense radiation. It also causes the appearance of extreme phenomena such as jets of relativistic particles, which travel at speeds close to that of light, or cosmic winds, flows of gas and particles ejected at thousands of kilometers per second from the internal regions.
This research, led by the Astrobiology Centerwith the participation also of the Institute of Astronomy and Astrophysics of the Academia Sinica, in Taiwan and the Large Telescope of Canary Islandssuggests that these extreme phenomena generated by the activity of supermassive black holes could be responsible for “altering the chemical evolution of the entire galaxy.”
The team of this study made a two-dimensional map of the relative abundances of oxygen and nitrogen in the gas of the active galaxy SDSS 1430+1339. This galaxy, located more than a billion light years from Landwas discovered by volunteers from the Galaxy Zoo citizen science project.
A bubble of hot, ionized gas
This quasar, Colloquially called Teacup due to its peculiar shape reminiscent of a tea cup, it is characterized by the presence of a bubble of hot, ionized gas with a diameter of more than thirty thousand light years surrounding its active nucleus. This bubble is associated with the presence of a huge flow of energy and high speed particles caused. The data obtained demonstrate that this flow, called “superwind”, acts as a powerful energy injection mechanism throughout the galaxy.
“Our study shows that the action of this superwind affects the chemical composition of the gas as it passes through the galaxy and that its impact reaches enormous distances,” said CSIC researcher at the Astrobiology Center and main author of the work, Montserrat. Villar. “If a similar phenomenon occurred in the heart of our galaxy, The resulting superwind could contaminate the gas with heavy elements in an enormous volume that would include the Solar system“, he clarified.
The variation in the relative abundances of oxygen and nitrogen observed across the Teacup Galaxy may be compatible with several scenarios. In all of them, nuclear activity associated with the supermassive black hole acts as the final responsible mechanism of chemical gas enrichment, even over long distances.
“We do not know whether the change in chemical abundances in the outer regions has been caused by the displacement of heavy elements from the central region of the galaxy or by other mechanisms that do not involve this drag. Another possibility is that this superwind has induced the formation of stars in areas very far from the galactic nucleus, and that these have enriched the surrounding environment through supernova explosions”.
“In any case, this quasar provides clear observational evidence of how nuclear activity can enrich the gas on large scales, possibly even beyond the galaxy itself,” added Villar.
The IAA-CSIC researcher and co-author of the study, Sara Cazzoli, added that “understanding how black holes supermassive galaxies regulate the evolution of galaxies one of the hottest topics in current astrophysics. “The interest of our study lies in that it provides direct evidence of its impact on the chemical evolution of the galaxy.”
The study team used integral field spectroscopy data obtained with the MUSE instrument on the Very Large Telescope (VLT), a suite of four telescopes 8.2 meters in diameter located in the facilities of the European Southern Observatory. The quality of the sky in that location and the sensitivity of the instrument have allowed detect and study in great detail the tenuous ionized gas that envelops active galaxies as distant as Teacup.
Analysis of the relative abundance and distribution of heavy elements in the gas of galaxies helps reconstruct the history of their chemical evolution, a crucial aspect in star and planetary formation. “This study is just the beginning, as it can be extended to many other galaxies. We have the theoretical tools and data necessary to investigate whether similar phenomena have occurred at different times in history. cosmic“, concluded Villar.
