Title Aktyvaus branduolio tėkmės įtaka juodosios skylės maitinimui /
Translation of Title The influence of an active nucleus-driven outflow on the feeding of the black hole.
Authors Jonauskas, Šarūnas
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Pages 22
Abstract [eng] In the center of our Galaxy, a ~ 4,3 · 10e6 Solar mass supermassive black hole (SMBH) named Sagittarius A* has been discovered. In many galaxies, SMBHs are known to be part of their centers, and their gravitational pull can affect the surrounding material, potentially contributing to the formation of new stars. According to observations by various teams of astronomers, young stars orbiting in eccentric elliptical rings have been found in the very nearest regions, a few parsecs in size, near the SMBH at the center of the Galaxy. This study aims to determine the mechanism responsible for their nature and how it affects the SMBH itself. The most likely answer is the feedback from the active galactic nucleus (AGN). The objectives of this study are: to investigate the morphological evolution of a cloud falling into the black hole and the feedback effect on it; to examine the dependencies of the black hole feeding rate and star formation in the falling cloud based of the strength and geometry of the feedback. The following conclusions were made: 1. As a molecular gas cloud falls into the black hole, elliptical gas disks are formed. Throughout the entire evolution period, the ellipticity is maintained. The dense gas ring prevents the newly formed stars from escaping the influence zone of the SMBH and has the potential to accrete into it. 2. The feedback from the SMBH affects its mass growth. Due to the generated luminosity, gas that approaches the SMBH is heated and pushed back into the system. This is sufficient to ensure that, over the entire evolution period, the mass growth of the SMBH is less than it would be if there were no feedback. 3. The feedback from the SMBH has little effect on the number and mass of the formed stars. A significant difference is observed in the model with conical feedback when the AGN is in its brightest state. The gas pushed back into the system has the opportunity to be absorbed into stars, thereby increasing the average stellar mass.
Dissertation Institution Vilniaus universitetas.
Type Master thesis
Language Lithuanian
Publication date 2024