WiNDS: An H$\alpha$ kinematics survey of nearby spiral galaxies -- Vertical perturbations in nearby disk-type galaxies

TL;DR

This study uses high-resolution Hα interferometry to analyze 40 nearby low-inclination spiral galaxies, identifying vertical velocity flows that suggest disk perturbations, thereby enhancing understanding of galactic disk dynamics.

Contribution

First comprehensive survey of vertical perturbations in nearby spiral galaxies using Hα kinematics, revealing the prevalence of such features in low-inclination disks.

Findings

20% of surveyed galaxies show strong vertical velocity perturbations

Vertical flows are associated with large vertical displacements of galactic disks

The survey provides new insights into the frequency of disk perturbations in the local universe

Abstract

We present the Waves in Nearby Disk galaxies Survey (WiNDS) consisting of 40 nearby low inclination disk galaxies observed through H$\alpha$ high-resolution Fabry Perot interferometry. WiNDS consists of 12 new galaxy observations and 28 data archived observations obtained from different galaxy surveys. We derive two-dimensional line-of-sight velocity fields that are analyzed to identify the possible presence of vertical velocity flows in the galactic disks of these low-inclination late-type galaxies using velocity residual maps, derived from the subtraction of an axisymmetric rotation model to rotational velocity map. Large and globally coherent flows in the line-of-sight velocity of nearly face-on galaxies can be associated with large vertical displacement of the disk with respect to its mid-plane. Our goal is to characterize how frequent vertical perturbations, such as those observed in the Milky Way, arise in the Local Universe. Our currently available data have allowed us to identify 20$\%$ of WiNDS galaxies with strong velocity perturbations that are consistent with vertically perturbed galactic disks.