Cone search table import dialogue
By selecting the Cone Search option from the Load Window's DataSources menu, you can obtain a dialogue which allows you to query one of a number of external web services for a catalogue of objects known in a given region of the sky.
There are a lot of cone search services out there, so the first thing is to decide which one you want to query. When this dialogue first appears you must fill in the Registry and Keywords fields at the top of the window. The Registry value defaults to the AstroGrid registry, but you can choose another if you prefer. In general, since the various registries harvest resources from each other, they can be expected to have similar content, but there will be exceptions. The Update button searches the currently selected registry for more registry services, so gives you a longer list of registries to choose from. The Keywords value is a space-separated list with no wildcarding. Each keyword is matched against the title, description, identifier, shortname and some other attributes to find matching services. By default a resource must match all of these to be selected, but you can toggle it to match any of them by clicking the And/Or button to the right of the selector.
Once these fields are filled in, hit the Submit button, and TOPCAT will query the selected registry for a list of the services which contain the chosen keywords. The services found will be displayed in the table. For more information about each one, use the Columns menu to select what information, such as publisher, reference URL etc is displayed in the table. You can scroll up and down this table and select the one which you want to query by clicking on it. The lower table lists the actual cone search services associated with each registry resource found. In most cases there is exactly one cone search service per resource, but if there is more than one you will need to select the one you want by clicking on it (it defaults to the first in the list).
Having selected one of the cone search services from the table, you need to specify the sky region in which you are interested. If you enter the name of an astronomical object into the Object Name field and hit the Resolve button, the coordinates will be entered into the RA and Dec fields below. Alternatively you can type the coordinates in directly, choosing either degrees or sexagesimal coordinates using the unit selector boxes. Enter the search radius too.
Having done this, hit the OK button. This will send the query to the service you selected and, if successful, load into TOPCAT a table containing all the objects in the region of the sky you have specified. The exact format of the returned table will depend on the service you have selected, but it will contain at least columns representing Right Ascension and Declination.
Note that this window requires certain optional components of the TOPCAT installation, and will not be available if you have the topcat-lite configuration.