Speaker
Description
Galaxy interactions and mergers are expected to redistribute baryons across galactic disks, yet how molecular gas and metals are reorganized as a function of merger stage remains poorly constrained. In this work, we investigate the radial structure of molecular gas and gas-phase metallicity using a large sample of nearby galaxies from the KILOGAS survey spanning a wide range of interaction stages. We construct radial profiles of molecular gas surface density and metallicity on a galaxy-by-galaxy basis and characterize their shapes. We find that a significant fraction of interacting galaxies exhibit deviations from single-slope profiles, and that the radial profiles of molecular gas and metallicity do not always evolve in a coupled manner. The inner molecular gas profiles become systematically steeper along the merger sequence compared to control galaxies matched in global properties, while the outer profiles appear comparatively flatter. This behavior is consistent with merger-driven gas inflows; however, these inflows do not lead to enhanced gas fractions in post-merger systems, likely due to rapid gas consumption by merger-triggered starburst. In contrast, metallicity profiles also tend to flatten with advancing merger stage, but the changes are less pronounced than those seen in molecular gas. Our results demonstrate that radial profile shapes provide a diagnostic of baryon redistribution during galaxy interactions and offer new constraints on the physical processes governing gas dynamics and chemical evolution.
To our knowledge, this study represents one of the first systematic attempts to quantify how the radial distribution of molecular gas evolves across the merger sequence in a statistically consistent framework.
| Participate the oral/poster presentation award competition | No |
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