you are here: VO Desktop2008beta-doc > V Odesktop Usage > Data Access Cone

Cone Search Examples

Querying the RC3 Catalogue

• Run up the VODesktop
• Run up TopCat
• In the VOExplorer window - select the Cone search examples from the Resource Lists/Examples list in the left window pane
• Select the Third Reference Catalogue of Galaxies
• In the Actions window - select Query
• This opens a new VOScope window
  • Select a Search Radius, e.g. 180 in Degree
• Hit the Search button
• This will bring up the search results' box in the main VOScope window. You will see 23011 results - the entire RC3 catalogue for the whole sky.
• Click on the results tab - and then in the Actions window Send the tables to Topcat
  • Sending the file to TopCat might take some time depending on the number of results. Look for the activity indicator in VO Scope during the transfer. Once the activity indicator ceases, it may still take a while for TopCat to order the results internally, and display them.
  • Hit the Speherical polar scatter plot icon - you'll then see the RC3 object distribution over the sky.
    • 

Querying the IRAS Point Source Catalogue

• Run up the VODesktop
• Run up TopCat
• In the VOExplorer window - select the Cone search examples from the Resource Lists/Examples list in the left window pane
• Select the 2MASS All-Sky Point Source Catalog

• In the Actions window - select Query

• This opens a new VOScope window
  • Select a position or object in the At Position of Object Name box
    • e.g. Crab - hit your keyboard TAB button which then will cause the coordinates to be returned to the position window - thus for the Crab nebula you should see 83.633208,+22.014472
    • e.g. 145.4375,+54.4564
  • Select a Search Radius, e.g. 0.1 in Degree
  • Note that you can switch between Decimal Degrees and Sexagesimal' by means of the radio buttons.
  • Hit the Search button
  • This will bring up the search results' box in the main VOScope window.

• Note that when the query is running there will be an activity indicator in the bottom left of the VOScope window.
• When the query returns there will be an indicator of the number of results.
• Click on the results tab - and then in the Actions window Send the tables to Topcat (or View the results in a web browser, or Download the results to a local file.
• Sending the file to TopCat might take some time depending on the number of results. Look for the activity indicator in VO Scope during the transfer. Once the activity indicator ceases, it may still take a while for TopCat to order the results internally, and display them. This plot shows the RA, Dec plot of the point source with the colour coding of their J magnitudes.