ASU Extensions for CDS-VizieR

This page contains the definitions of the extensions to Astronomical Server URL (ASU) adopted at CDS, essentially for the Aladin usage; and for the data-mining project.

Summary of ASU Extensions at CDS:

Contents:

1  -out

Some additional conventions to denote the columns are used in VizieR:
* indicates all default columns;
** indicates all columns (not only the default ones)
*mime(type) indicates the columns with a link to the specified mime type
*ucd indicates the columns corresponding to the specifed UCD
_V a column with just the letter V as a link to the full record
_r the distance from the center
_x the distance from the center projected toward East
_y the distance from the center projected toward North
_RA(Equinox,Epoch) the right ascension in another coordinate frame
_DE(Equinox,Epoch) the declination in another coordinate frame
_Glon the galactic longitude
_Glat the galactic latitude

2  -meta

The following META queries were implemented in the vizglu program, which is aimed to query for GLU (Générateur de Liens Uniforme) usage:

-meta.all
lists all metadata (column descriptions)
-meta.what
lists the existing possibilities of the -meta query facilities
-meta.max=n
defines the limit of the catalogues retrieved (default: 100)
-meta.acros
lists the catalogue acronyms known in VizieR.
-meta.survey
lists the catalogue acronyms related to large surveys — typically reference lists covering the whole sky and containing at least 500×106 objects.
-meta.kw
lists the complete set of keywords known in VizieR. The keywords are grouped by categories (currently 3 categories)
-meta.ucd
show the UCDs attached to each column

3  -survey

This option simply eliminates the survey catalogues from the list of catalogues. This option could be implemented as a keyword, but is not presently.

4  Usage of Lists in VizieR

For lists – typically a list of target objects or positions on the sky – the following format is used:

constraint_name=<<====sentinel
............
====sentinel

i.e. the first line contains the delimiter or sentinel placed immediately after the << sign. This sentinel indicates the end of the list; to be recognized, it has to be placed at the left margin.

As an example, the following is a list of targets: 

-c=<<======EndListOfTargets===

3C 273
NGC 4321
======EndListOfTargets===