![]() In the ancient Universe there was much more available gas, so the effect of a process such as that described by him was more intense, May explained. The black hole is known about only from its effects." All the information that reaches us from it corresponds to a pixel, so we don't have enough resolution to discern its possible parts. The accretion disk appears as an extremely bright spot. "We see the walls fragmenting and the ionized gas being driven out. ![]() "When we observe the central regions of these two galaxies, we see this enormous bubble in profile, delineated by its walls of molecules," May said. For the sake of comparison, it is worth recalling that this is almost 70 times the distance from Earth to Proxima Centauri, the nearest star to the Solar System. As it fragments, it is pushed further out in an expanding hot bubble that can be as large as 300 light years in radius. The ionized gas derives from fragmentation of this molecular gas, May explained. We were able to relate the two phases of the gas, previously considered disconnected, and fit their morphologies into a single scenario." We discovered that the molecular part is entirely tied to the ionized part, which is known as the outflow. As the cloud is sucked into the disk, two distinct phases take shape: one is ionized owing to exposure to the disk, and the other is molecular and overshadowed by its radiation. The photons emitted by the disk, which reaches temperatures on the order of a million degrees, push most of the gas a long way outward, while a smaller part of the gas is absorbed by the disk and eventually plunges into the black hole. "Our study suggests that initially a cloud of molecular gas in the central region of the galaxy collapses and activates its nucleus, forming the accretion disk. We investigated the individual characteristics of these two objects in an almost artisanal manner," May said. ![]() Most astronomers today are interested in studying very large datasets. "Using a highly meticulous image treatment methodology, we identified the same pattern in two very different galaxies. NGC stands for New General Catalogue of Nebulae and Clusters of Stars, established in the late nineteenth century. May identified the pattern on the basis of a study of two active galaxies: NGC 1068, which he investigated in 2017, and NGC 4151, which he investigated in 2020. João Steiner, Full Professor at IAG-USP and a co-author of the article, supervised May's Ph.D. The study was supported by FAPESP via a doctoral scholarship and a postdoctoral scholarship awarded to May. This means there's far more matter being blown away from the center, and the active galactic nucleus plays a much more important role in the structuring of the galaxy as a whole," May told Agência FAPESP.Īn article on the study by May and collaborators is published in the journal Monthly Notices of the Royal Astronomical Society. "We found that the molecular phase, which appears to have completely different dynamics from the ionized phase, is also part of the outflow. The traditional model posits two phases in the matter that accumulates in the central region of an active galaxy: a high-speed ionized gas outflow of matter ejected by the nucleus, and slower molecules that may flow into the nucleus.Ī new model that integrates the two phases into a single scenario has now been put forward by Daniel May, a postdoctoral researcher in the University of São Paulo's Institute of Astronomy, Geophysics and Atmospheric Sciences (IAG-USP) in Brazil. Those that do are known as active galaxies, on account of their active galactic nuclei. Every galaxy is thought to have a supermassive black hole at its center, but not all galaxies have, or still have, accretion disks.
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