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How to use the GALEX Sky. Node* A quick tutorial by the MAST/GALEX Team at STSc. I *Sky. Node was developed and is maintained by JHU staff 1. 1
What is Sky. Node? l Sky. Node is the interface to a prototype of a “federated” database application called Sky. Query. l At the heart of Sky. Query is spatial matching, which means we want to find the same objects listed in different catalogs. l Astronomical archives double every year. Increasingly, data are stored in on-line archives. Instrumental surveys covering a large fraction of the sky are a major part of this revolution. Sky. Query relies on surveys stored at different geographic locations.
Sky. Query: Interface • The Sky. Query interface window is divided in 2 parts: 1. The list of Sky. Nodes can be queried by marking checkboxes 2. A SQL-like text box is used to submit queries
Sky. Query: consult a Sky. Node’s parameters. Step 1 The contents of each Sky. Node can be browsed. • Select a survey and its list of tables or functions. Click Search. • From the entries returned, enter any column/function of interest in Argument. Click Search.
Sky. Query: consult a Sky. Node’s parameters. Step 2 • To build a query, we need to know what keywords to use in table e. g. Photo. Primary, so select Columns(Table. Name). • Now run Steps 1 and 2 for another Sky. Node(s). Columns from Photo. Primary Now we are ready to run the query…
Run an ADQL (SQL-like) query • • • Running a query is simple. Write it in the SQL-like query box or … Click and customize any of 4 sample queries, #1, #2 … See also “tutorial” http: //www. skyquery. net/ tutorial. html • To submit query, click Submit. Cross correlation results appear! (ra, dec, radius)