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Carlsberg Meridian Catalogue 14
Carlsberg Meridian Catalogue 14 (webpage) was released on 31 December 2005. This is an astrometric and photometric catalogue of 95.9 million stars in the red (SDSS r') magnitude range 9 to 17. This catalogue is the next release of the CMT CCD survey and covers the declination range -30° to +50°.
The AstroGrid access to the CMC14 catalogue provides two interfaces. An ADQL interface and a simple Cone Search interface. The first one is used to submit ADQL (Astronomical Data Query Language; similar to SQL) directly to the database, allowing for a flexible search to be performed. For a tutorial on how to do this you can go to the IPHAS example section.
The second interface allows for a simple Cone Search around a position and is the one described below.
Performing a cone search
One peculiarity of the CMC14 cone search is that it is really a box search, i.e., returns all objects in a box specified by ra and dec and size radius.
Once the Workbench is launched, select the Task Launcher and search for cmc14. Click on thick box at the left of the entry name and select 'cone' in the drop down menu.
An interface like the one shown in the screenshot below will appear. Insert there the center of the box in the RA and Dec entries (in degrees) and the size of the box in Radius (also in degrees). In the outputs section click on the tick box under the 'Ref' label and use the file browser to select a file in MySpace. You will notice that the format is 'VOTABLE'. You can also introduce 'HTML' to obtain the table in a HTML formatted document, or 'Comma-Separated' to obtain it as a CSV file.
You can then click on the green arrow in the toolbar to execute the task, or in the save icon to save the task in a file to be executed later.
Using AstroScope
The contents of the catalogue can also be browsed together with all the catalogues in a search region specified by the user with AstroScope. Below a screenshot of AstroScope showing all catalogues and the objects they contains around a position in sky.
Calling the cone search from a script
It is possible to access the cone search service without launching the workbench. The URL to do that is http://casu.ast.cam.ac.uk:8086/CMC14-catalogue/SubmitCone?RA=1.0&DEC=3.0&RADIUS=0.167 (remember that all arguments must be in degrees).
Note however that scripts using this method rely on the service being on a static URL address. If this URL changes the script will stop working. Using the Workbench is the way of making sure that you are calling the correct service.