This service lets you run simple positional crossmatches against all tables available for ADQL querying in XAO's data center by simple file uploads or URL referrals. Tables you can match against include GAIA,SPM4,ATNF Pulsar Catalog, and PPMXL (we recommend the latter for adding proper motions).
To find out more about the tables given, consult the list of tables available for ADQL. Not all tables given there are suitable for cross matches (if you complain, we will restrict the selection in the form to those that are, but so far no one has complained). If you think we should have additional catalogs you can crossmatch against, let us know and we'll see what we can do.
The uploaded VOTables must have exactly one pair of columns with UCDs of either pos.eq.[ra|dec];meta.main or POS_EQ_[RA|DEC]_MAIN. The results of VO cone searches work well.
If you have tables of your own, you will first have to bring them to the VOTable format. A good tool to do that is Topcat . It allows you to convert almost arbitrary data to VOTables.
You must, however, mark up what columns are the positions you want to match agains; this is what the jargon with "UCDs" above means. To do this, in Topcat select "Views/Column Info". The table in the window that pops up has a column UCD, the contents of which are editable by clicking into the field. Enter pos.eq.ra;meta.main in the column of the relevant right ascension, and pos.eq.dec;meta.main in the column of the relevant declination.
We currently do not support transformation of your coordinates, so you have to make sure that the input coordinates match the system used in the table (for basically all of our tables, this means ICRS or FK5 J2000 to an accuracy sufficient for matching).
If you need fancier facilities, use our ADQL service.
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