Probing the Assembly Histories of Quenched Galaxies via Population-Orbit Superposition Method

We present a study of quenched galaxies using the population-orbit superposition method in the context of GECKOS—a VLT/MUSE large program targeting 35 nearby edge-on galaxies. GECKOS provides a unique sample of isolated quenched spirals, enabling us to investigate the internal mechanisms driving star formation shutdown in the absence of strong environmental influences. By fitting stellar kinematics, age/metallicity maps, we obtain stellar orbital distributions, which allow us to decompose each galaxy into cold, warm, and hot orbital components to trace their assembly histories. Our models reveal the detailed assembly history of quenched spirals, highlighting the role of internal processes. To contextualize these findings, we compare our results with quenched galaxies from the Fornax3D survey, which reside in a dense cluster environment. This comparison underscores the role of environment in shaping quenching pathways: isolated systems exhibit distinct signatures of secular evolution, while cluster galaxies show stronger environmental imprints. By integrating spatially-resolved MUSE data with dynamical models, we bridge the gap between small-scale processes and global galaxy properties. This approach provides new insights into the baryon cycle and the relative contributions of in-situ versus ex-situ processes in galaxy assembly, aligning with the conference's focus on resolved galaxy evolution.