Summary of ASU qualifications for VizieR

The generic URL used in ASU follows the generic rules of the HTTP protocol (RFC 1945):

http://root_URL?arg1&arg2&...
where the ampersand &) separates the arguments when there is more than a single argument. The HTTP protocol also specifies that any special character (blank, quotes, and + * < > & # ) exsiting in an argument should be encoded by a percent sign (%) followed by its ascii hexadecimal representation. The blank must therefore be replaced by %20, the + sign by %2b, etc.

The root URL to get results from VizieR is

In the root URL, the host name (vizier.cds.unistra.fr) may be replaced by one of the mirrors: vizier.ast.cam.ac.uk, vizier.cfa.harvard.edu, vizier.hia.nrc.ca, vizier.nao.ac.jp, vizier.iucaa.ernet.in, vizier.inasan.ru, vizier.bao.ac.cn, vizier.ukirt.jach.hawaii.edu.

Following the question mark (?), the ASU arguments are written in the general form name=value The following conventions about name are used:

Specifying a Choice of Catalogues:   there are several ways of designating catalogues; the fastest is to use the catalog identification assigned in VizieR like -source=I/239/hip_main for the main Hipparcos catalog.

-source= catalog(s) to query (Several catalogs may be specified if separated by a comma or a blank).
Well-known catalog abbreviations may be used – the full list of abbreviations known in VizieR can be listed.
-words= names or words of title of catalog. The words are and'ed, i.e. only the catalogues characterized by all the words are selected.
-kw= keyword in any of the 3 lists by Wavelength, Mission, or Astronomy.
If several keywords are given on the line, they are or'ed; but if several lines with -kw=value exist, their content is and'ed.
-ucd= designation of UCD
The catalogues having one or more columns matching the specified UCD(s) are selected; the * may be used as a wild character, e.g. PHOT_*_B represents a blue photometry which can be in a lot of different photometric systems.
Several -ucd=value can be used to select catalogues having simulteously the properties specified by the UCDs; in other terms, similalry to -kw, UCDs specified on the same line are or'ed, while the different lines are and'ed.
-pos restricts to tables containing celestial positions
-phot restricts to tables containing well-defined photometry
-nosurvey restricts the choice to catalogues outside the ``survey'' list of catalogues.
-obsolete asks to include the obsoleted versions of catalogues in the set.
-corr= correlation for a fine-grain selection of tables:
-corr=pos restricts to tables having a position;
-corr=name=col_name restricts to tables having the specified col_name among its columns;
-corr=PK=col_name restricts to tables having the specified col_name and this column is a primary key of the table;
-corr=FK=col_name restricts to tables having the specified col_name and this column is a foreign key of the table;

Target Center:   the specification of a target requires a center – a position in the sky – and a geometry around the center. Only a circle/annulus, and a rectangular box, are available.

-c= defines the center of the target
There are many possibilities of specifying the center – by object name, position in sexagesimal or decimal degrees. For equatorial positions, remember that a sign must exist before the declination, and that no decimal point in the RA part implies a sexagesimal position (i.e. 15 +12 means 15h+12°, but 15.+12 means 15°+12°, or 1h+12°.
-c.eq= defines the equinox of the position given in the -c argument. Note that this parameter is not useful when the target is specified by a name.
Typical examples are -c.eq=B1950 or -c.eq=Gal
The default is -c.eq=J2000
-c.rm= defines the radius of the target in arcminutes.
Two numbers may be specified: in the case, the target is an annulus.
-c.rd= defines the radius of the target in degrees.
-c.rs= defines the radius of the target in arcsec.
-c.bm= defines a rectangular box of horizontal/vertical dimensions in arcmin, as e.g. -c.bm=8x6
-c.bd= defines a rectangular box in degrees
-c.bs= defines a rectangular box in arcsec.
-box= defines a rectangular box using IAU-conventions, e.g. J0000-00 for a box in J2000 coordinates containing the positions having their RA between 0h0m and 0h1m and their declination between and –1° This convention is valid also with other coordinate systems: Bhhmm...±dd... (B1950 position), Glon...±lat... (galactic position), S... (supergalactic) and E (ecliptic).
Finally a box may also be represented by a qbox value, the systems of cells used to access by positions (described briefly in the qbox man page)

Output Contents:   the contents and order of the result can be specified by the following arguments:
-meta No actual query is performed, only the tables involved in the query are described. This is useful to get an idea of which catalogues exist which share e.g. a keyword.
-meta.all similar to -meta, but all metadata (details of columns) are listed.
-meta.max= specifies the maximal number of catalogs to be listed (the default is 500)
-out= specifies the result columns to list in the output; -out= is normally followed by a list of column names (separated by blanks) to be displayed.
The list may contain, in addition to standard column names:
  • computed columns: names starting by an underscore (_)
    _r Distance from the target center
    _x Horizontal distance from the target center (East)
    _y Vertical distance from the target center (North)
    _pa Position angle (North through East) of vector from the target center (degrees)
    _key The column representing a key (identifier) of a row (typically the recno counter when that one exists)
    _ID a string which identifies a row, in the form name=value (typically recno=record_counter)
    _RA(Equinox, Epoch) Computed right ascension for a specified frame / equinox / epoch with the standard conventions: ICRS represents the ICRS frame, J2000 represents the FK5(J2000)/ICRS frame, and B1950 the FK4(B1950) frame.
    _RA _RAJ or _RAJ2000 are a shorthand for _RA(J2000,J2000)
    _RAJ() is a shorthand for _RA(J2000) (keeping the epoch)
    _RAB or _RAB1950 are a shorthand for _RA(B1950,B1950).
    _DE(Equinox, Epoch) Computed declination, using the same conventions as _RA
    _GLON Computed galactic longitude
    _GLAT Computed galactic latitude
    _SGLAT Computed supergalactic latitude
    _SGLON Computed supergalactic longitude
    _1 Name of target or input constraint (applies to lists)
    _q Counter (from 1) of target number (applies to lists)
    _V A http link to the row being edited. _V may be followed by a text which will be used in the link.
    _sed0 Minimal details to build an SED (Spectral Energy Distribution): edit the columns containing magnitudes or fluxes in well-identifier filters, wavelengths or frequencies.
    _sed1 In addition to _sed0, compute the flux (in Jy)
    _sed3 Present the SED as 3 vectors: (1) frequencies (GHz), (2) fluxes (Jy) and (3) errors on fluxes (Jy)
    _sed4 Present the SED as a set of formatted SED points; one point is formatted as GHz=Jy[errJy]${col}[filter] e.g. 241.77e+3=31.3[0.8]e-3${Jmag}[2MASS:J] for a flux in the 2MASS J-band, or 353.00=8.91[0.21]${S}@{Freq} for a flux from the column S and the frequency from the column Freq.

  • ucd-specified columns: names starting with an asterisk * and followed by an UCD like e.g. *meta.id;meta.main
  • columns with links to images: *Mime(image/fits)
  • the list of the default columns: specified by a single asterisk *
  • the list of all columns: specified by a double asterisk **
-out.all Display all columns (i.e. -out.all is equivalent to -out=**)
-out.add= List of columns to add to the standard set, e.g. -out.add=_r lists the distance to the target
-out.max= Maximal number of rows to retrieve (default is 50)
-out.meta= Some options on the descriptions of the columns, as a set of characters referring to the possible additional details; the list may be preceded by + or - for addition or removal of the following elements:
h (header) add the column names
u (unit) add the units of each column
U (UCD1) give the UCD1 (default is UCD1+)
2 (2UCDs) give the two UCDs (UCD1 and UCD1+)
D (Description) adds the description of columns
L (Links) add the definition of Links (may result in more columns than what was asked)

The default is huD; to get for instance the 2 UCDs, add   -out.meta=+2
-out.form= Some options on the output:
DTD (for VOTable output): use the DTD definition rather than the standard XML-Schema
bin64 (for VOTable output): use a binary 64-encoded output for the data
TSV (for VOTable output): use a Tab-Separated-Values representation of the data (the Astrores way)
groups (for VOTable output): use the groups of columns introduced in VOTable1.1
mini (for lists): minimize the output, i.e. keep a single table which gathers the results of the list (the list must be applied to a single table)
-sort= Sort order, e.g. -sort=_r to sort by increasing distance to the target. A minus sign before the column name (e.g. -sort=-_r) indicates a decreasing order.
-oc.form form of the computed position, as -oc.form=d for decimal degrees, or-oc.form=s for sexagesimal representations. An optional M (Main) can be added to specify that the UCD qualification main main is added to the computed position (by default this main qualification is attached to the original position)

Joining tables:   Two or more tables can be combined or joined into a single table; some details and examples can be found in the join documentation. The following argments are specific to joins:

-joincol specifies the column used in the join (the name must be shared among the tables involved).
-outjoin specifies the table.column of the referent column in the case of outer joins.

Issuing several queries:   Independant queries can be issued in a single request, using a -go separator. More control can be specified in the case of votable output:


2012-12-12 — François Ochsenbein () <&CDS.headStuff2><&CDS.tailArea2 "/home/cds/httpd/Pages/doc/catstd/asu-summary.htx" "" "">