The kinematic imprinting of environmental quenching in $z<0.2$ galaxies

TL;DR

This study uses kinematic asymmetries in galaxies from the MaNGA survey to identify quenching mechanisms, revealing that environment-driven rapid gas stripping followed by slow starvation is a dominant pathway for galaxy quenching in the local universe.

Contribution

It provides the first systematic analysis of kinematic signatures of quenching mechanisms in a large galaxy sample, distinguishing between environmental and internal processes.

Findings

Quenched symmetric satellites are more compact than asymmetric ones.

Environmental quenching involves rapid gas stripping and long-term starvation.

Internal processes like AGN feedback sustain quenching over 1-3 Gyr.

Abstract

We present the first systematic census of quenching mechanisms using kinematic asymmetries in a large sample of $\sim$6,700 galaxies from the MaNGA survey, providing a unified view of what halts star formation in the local Universe ($z<0.2$). We quantify stellar and nebular gas disturbances through the higher-order terms of a Fourier series expansion. These asymmetries serve as powerful diagnostics, as different quenching mechanisms leave distinct kinematic signatures on gas and stars. Our analysis reveals that the most effective quenching pathways leave minimal kinematic imprints by the time galaxies are fully quenched. This "kinematic regularity" points toward slow-acting processes (>3 Gyr) such as starvation and maintenance feedback. A striking finding emerges from our mass-matched analysis: quenched symmetric satellites are significantly more compact than their asymmetric counterparts ($3.4\sigma$), a trend that is even more pronounced for symmetric centrals ($12.3\sigma$). Our results suggest that environment drives the dominant satellite quenching pathway through rapid gas stripping followed by long-term starvation. These compact, kinematically undisturbed satellites (the most representative case within our sample) have undergone intense gas stripping and central compaction, creating bulge-like structures with old, metal-rich stellar populations. Combined with halo gas cut-off and the prevention of cosmological accretion due to starvation, this creates an irreversible quenching path. Conversely, the larger sizes of disturbed, quenched centrals are consistent with merger-driven growth. Internal processes, likely driven by the AGN cycle over 1-3 Gyr that prevents hot halo gas cooling, sustain quenching maintenance in this population. The absence of asymmetric satellites in the star-forming regime suggests environmental quenching operates without significant kinematic perturbation.