| Resumo : |
This thesis investigates the role of AGN in influencing the molecular gas dynamics and star formation within their host galaxies, focusing on the TWIST sample of nearby AGN host galaxies. Using high-resolution CO(2-1) data from the ALMA and multi-wavelength observations, we analyze the interaction between AGNs and the interstellar medium (ISM), examining how AGN activity drives gas inflows and outflows that shape galaxy evolution. Our study begins with a detailed analysis of NGC 4593, a Seyfert 1 galaxy with a prominent bar and active nucleus. We used ALMA CO(2-1) observations alongside 3D-Barolo and discFit kinematic modeling to assess gas distribution and dynamics. The modeling reveals a complex structure, including a central molecular zone (CMZ)-like ring with strong rotational motion and significant non-circular features aligned with the bar potential. We detect a molecular outflow along the galaxy's minor axis, extending approximately 220 pc from the nucleus and comprising about 10% of the galaxy's total CO(2-1) flux. The estimated total molecular gas mass is 1 ? 5 × 108 M?,, and the supermassive black hole (SMBH) mass is calculated to be log (MBH /M? ) = 6.89 ± 0.04. Spectral energy distribution (SED) modeling with CIGALE reveals an AGN fraction of 0.88 and a moderate star formation rate of 0.42 M? yr?1 . Building on this framework, we applied the same methodology to 20 additional galaxies within the TWIST sample. For each galaxy, we derived the kinematics and morphology of the molecular gas using 3D-Barolo and performed spectral energy distribution fitting with CIGALE to determine star formation rates, AGN luminosities, AGN fractions, stellar masses, molecular gas masses, and black hole masses. Our analysis identified clear signatures of either gas inflows or outflows in several galaxies, enabling us to calculate outflow mass rates for roughly 20 of the 41 galaxies studied. |