Dra. Patricia da Silva
Abstract: One of the most discussed topics of modern astrophysics is the interaction of the nuclei of galaxies with their host. It is known by the relation of the mass of the supermassive black hole (SMBH) and galactic properties (such as m-sigma) that there is evidence of a co-evolution between the two. Many studies are being made regarding the feeding and feedback processes, the interactions and influence of one to another. A way of studying that is how the gas of the disk of the galaxies falls into the center and feeds the nuclear region, consequently the SMBH, activating it. We selected galaxies with the same morphological type as the Milky Way (which is known for having a gas-rich nuclear region, however a non-active nucleus), and non-barred counterparts. The goal of this study is to investigate the nuclear region of those galaxies, the molecular gas dynamics between 1kpc and 100 pc, and what is the influence of the bar in this context. Our sample comprises 10 galaxies: 8 barred (SABbc and SBbc) and 2 non-barred (SAbc). We found out that, in most of the barred sample, the nuclei present a diversification of structures, such as rings and nuclear bars. We did not detect any influence of AGN in those scales. The bar exerces negative torques on the molecular gas, making it fall into the nuclear region, by the loss of angular momentum. The non-barred galaxies present no relevant torques, and one of them has no identifiable structure in the nuclear region. The infalling of gas together with the bar influence are responsible for the structures that we observe in the nuclear region, such as rings. Those rings can prevent the gas to keep falling, that would explain the low activity on those galaxies. However, bars and rings are not a permanent feature. Once dissolved, the scenario on the nucleus can change, feeding more effectively the SMBH.
Mini-bio: Patricia da Silva tem mestrado em Astronomia pelo Instituto de Astronomia, Geofísica e Ciências Atmosféricas e doutorado adquirido no mesmo instituto. Tem experiência na área de Astrofísica, com ênfase no estudo de núcleos de galáxias (AGNs e núcleos não ativos) utilizando análises de espectroscopia 3D.
Google Meet: https://meet.google.com/pcw-gmem-jyi
Link da transmissão: https://www.youtube.com/c/AstronomiaIAGUSP/live