Virtual Observatory Software for Astronomers

Notes on Helper Applications

A number of applications are available though the VODesktop which can be used to work with data returned from queries and so forth on the desktop. These Helper Applications are tools for visualising and analysing data which are able to exchange data readily using a VO protocol called Plastic. The tools run on your laptop or workstation. Some of the applications available include:

Obtaining Applications

The Helper Applications are maintained by a range of organisations and individuals and the home page links given above and via the Plastic page describe how to obtain them.

Tip: Many university academic establishments will already have some applications e.g. TopCat available on a common-user system. If you have trouble with these, check that you are running the version listed on the Plastic page links.

In most cases you will download or install a java package; at its simplest you might then run it by typing e.g. java -jar -topcat-full.jar

Tip: If you want to load a large table or image you can increase the available memory e.g. java -jar -Xmx512M topcat-full.jar

Some applications also (or only) run in a browser using java webstart.

Use

You need to have the AstroGrid VODesktop running. Most of the applications will automatically connect to the Plastic Hub and also have a button for manual connection if necessary.

Java Applications and Memory

TopCat

It's a good idea to run TopCat with a reasonable amount of memory.

If you download and install the MacOS version as a .app file - you'll need to edit the Application info.plist file.

  • To set the memory option, control-click on the TopCat icon in the Finder (TopCat probably lives in Applications), select "Show package contents" and edit the Info.plist file (which is in the Contents directory. Search at the bottom of the file for the key "VMOptions" and add it there, after any -Xmx statement. For example, for a machine with 2Gb of RAM, you could set the memory to 1024Mb so add in (make sure you only have spaces and no TABs in the file!) : 
      <key>VMOptions</key>
  <string>-Xmx1024M</string>

Transferring data

If you run a query which returns a table or an image, for example, and select the output in the AstroGrid window, icons will appear which offer any suitable Plasticised tools as a destination.

Interoperability

You can also transfer suitable data between applications (e.g. edit a table in TopCat and send it to Aladin) and even make selections in one application which are displayed in another.

Acknowledging AstroGrid. If you make use of the AstroGrid system or tools, we would be grateful if you could acknowledge this use in any resulting publications. You could use these words: 'This research has made use of data obtained using, or software provided by, the UK's AstroGrid Virtual Observatory Project, which is funded by the Science and Technology Facilities Council and through the EU's Framework 6 programme.' Use of any data discovered or accessed through AstroGrid should of course be mentioned as noted by the data providers.

Licensing and Copyright. AstroGrid software is released under the Academic Free License.. The copyright on the text used in these web pages is owned by the contributing authors. Copyright on images used are assumed to be with the indicated or implied source as appropriate.