Centre de données astronomiques de Strasbourg
The Strasbourg astronomical data center (CDS) provides reference astronomical services:
- SIMBAD is the reference database for identification and bibliography of astronomical objects (outside the solar system).
- VizieR is a catalogue service for large sky surveys, catalogues and tables published in academic papers, and more and more other data associated to publications.
- The interactive sky atlas Aladin provides an interactive portal to access image collections and databases available via Virtual Observatory protocols.
- The CDS cross-match service allows to do positional cross-matching of very large catalogues.
The Aladin data collections tree provides access to many data collections.
- The selection of a leaf gives access to all data associated to the corresponding data set: depending on the collection type (images, catalogues, cubes), several data products can be available.
- The access selector can be pinned, so it will remain opened as a window.
- For image surveys, you can access the HiPS images : hierarchical progressive views, where you can zoom locally or view the full sky.
- You can also view the survey coverage, with the MOC (multi-order coverage map).
- And in some cases, you can find the progenitors of the HiPS, that is the original individual images that have been mosaicked to produce the HiPS survey. For each image, we have its footprint, and we can retrieve it.
- For catalogues, you can load all sources in the current field of view.
- Or define a precise cone, and retrieve sources in this region.
- You can also have a progressive access, useful for large catalogues, where more and more sources are loaded as you zoom in.
- You can also use an existing catalogue plane to perform a cross-match against any catalogue, or use the "by criteria" button to make a complex query using the Table Access Protocol defined in the Virtual Observatory standard.
- For some catalogues, you can load a HiPS corresponding to the source density map of the catalogue, or load the MOC to see the coverage on the sky.
- Last but not least, the selection of several leaves simultaneously (by pressing CTRL while clicking) provides other data access, for instance the union or the intersection of the data sets coverages.
Download Aladin desktop : http://aladin.u-strasbg.fr/java/nph-aladin.pl?frame=downloading