Tilted-ring modelling of disk galaxies: Anomalous gas

We report our ongoing work on kinematical modelling of H i in disk galaxies. We employ our new software TiRiFiC (Tilted-Ring-Fitting-Code) in order to derive tilted-ring models by fitting artificial H i data cubes to observed ones in an automated process. With this technique we derive very reliable parametrisations of the H i disks. Having such model parametrisations at hand, one can detect easily “anomalous gas” as residuals in the observed data. The residuals themselves can be analysed directly or can again be parametrised in order to learn more about the structure and the origin of the anomalous gas component.