%ABanik, Uddipan%AWeinberg, Martin%Avan den Bosch, Frank%BJournal Name: The Astrophysical Journal; Journal Volume: 935; Journal Issue: 2; Related Information: CHORUS Timestamp: 2024-01-16 11:55:49 %D2022%IDOI PREFIX: 10.3847 %JJournal Name: The Astrophysical Journal; Journal Volume: 935; Journal Issue: 2; Related Information: CHORUS Timestamp: 2024-01-16 11:55:49 %K %MOSTI ID: 10370067 %PMedium: X; Size: Article No. 135 %TA Comprehensive Perturbative Formalism for Phase Mixing in Perturbed Disks. I. Phase Spirals in an Infinite, Isothermal Slab %X
Galactic disks are highly responsive systems that often undergo external perturbations and subsequent collisionless equilibration, predominantly via phase mixing. We use linear perturbation theory to study the response of infinite isothermal slab analogs of disks to perturbations with diverse spatiotemporal characteristics. Without self-gravity of the response, the dominant Fourier modes that get excited in a disk are the bending and breathing modes, which, due to vertical phase mixing, trigger local phase-space spirals that are one- and two-armed, respectively. We demonstrate how the lateral streaming motion of slab stars causes phase spirals to damp out over time. The ratio of the perturbation timescale (