National Virtual Observatory : Quick Region Inventory

Please Contact us with any questions or problems with this service.


Search Form

The VAO Sky Statistics tool is actually five services in one. For a circular aperture on the sky, it searches a set of custom data structures to determine which VAO-accessible catalogs have data in that region. So far, the service covers the IRSA, NED, and CDS VizieR holdings with more in process (several thousand catalogs in all).

Source Counts

For each catalogs covering the region, the results of the basic sky statistics search include a count of sources, a shorthand catalog ID (which links to the appropriate archive-specific data download service and can be used to retrieve the catalog subset), the catalog description (which links to catalog-specific documentation) and a thumbnail all-sky coverage map (in Galactic coordinates.

Coverage Maps

The thumbnail link in the source count table above links to a service which shows set of pre-generated coverage maps for the catalog: Equatorial and Galactic; source density and coverage masks; JPEG and FITS; and different resolutions.

Composite Coverage

The last column in the source count table is a checkbox. Several catalogs can be selected on this page and then one of two "composite" views can be generated. The first is a composite all-sky coverage map, showing the fraction of the selected catalogs with data in the map pixels (this does not imply the catalogs have sources in common, however). Also generated is a map of just those pixels covered by all the selected catalogs.

Region Map

The other composite is a source map for the original region of interest, showing the exact location of all the sources from the selected catalog.