The Main Window shows an interactive view of the galactic plane (longitude from -180° to +180° and latitude from -2° to 2°). This view can be used to perform a visual selection of the region of interest.
The selection of the region can be carried out choosing a point on the map and then specifying the radius of selection, or picking up a rectangular region.
It is also possible to specify the surveys and wavelengths for the VLKB query using the checkboxes on the right panel.
Clicking on the Query button, VLVA sends the query to the VLKB and then opens on a separate window the FITS image containing selected region, in the chosen survey and wavelength, that is used as starting point for performing the visual analytic operations.
VLVA allows to load a FITS file image that is locally stored on the user’s computer by clicking on the Local Image button.
Similarly, the Local DC button allows to load and visualize a velocity datacube FITS file that is already stored on a local disk. When loading a datacube, VLVA will also compute the zeroth moment map which will be visualized as a 2D image layer. The VLKB search functionality is also extended to imported files.
The Select button under the 3D section allows to specify the range of coordinates on which to perform a 3D visualization of compact sources on the galactic plane (3D visualization of compact sources).