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How to select catalogues
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From the first VizieR Service page, three different access possibilites to select catalogues are proposed:

1. Direct access to Catalogues from Name or Designation

to your favorites Catalogues. The Catalogues can be designated

by their usual acronym or abbreviation like NGC, HIP, USNO2, etc... (full list of acronyms known in VizieR)
by their CDS/ADC designation like I/239 or 1239 assigned to the Hipparcos catalogues, or J/A+A/275/101 for the tables associated to the publication in A&A 275, 101 (full list of Designations known in VizieR). The designation may specify a unique table, like VII/224/table2 which represents the table of confirmed, probable or possible BL Lac objects in Véron and Véron compilation of quasars (10^th Ed., 2001).

Note that

several catalogues can be entered, separated by blanks or commas, like
Tycho-2,USNO2
for the Tycho-2 and the USNO-A2 catalogues.
the * (asterisk) can be used as wild character, and you may for example get all catalogues of the IX category (high-energy catalogues) by entering
IX/*

2. Selection by word or keyword, and vicinity to a target.

Five possible inputs are available to locate the catalogues:

a box where free words like author's name(s), word(s) out of the title or description may be typed in;
a box with wavelength keywords;
a box with Mission keywords;
a box with astronomy-oriented keywords;
a choice of a target which defines a region on the sky.

The choices specified in each of the boxes are anded, which means that choosing keywords e.g. X-ray in the leftmost box, Rosat as a Mission name, and Galaxy in the rightmost box, will locate catalogues observed in the X-ray waveband, with the Rosat satellite, and dealing with galaxies. Entering qualifications in several of the proposed boxes will therefore rapidly result in an empty set.

Within each of the keyword boxes, the various items which may be selected are ored, which means that e.g. selecting simultaneously Radio and IR items in the leftmost box will restrict the choice to catalogues dealing with Radio data or IR data. (with some interfaces, you may have to push down the Control key to remove one item or to select several items)

In the "free words" (top) box, you may enter one or several words which are simultaneously found in a short description of the catalogue, which includes author's names, the title, and a short summary. For instance, typing
cfa redshift
will locate catalogues quoting these two words in any order.

Note that

words made of 1 or 2 letters are normally ignored (there are a few exceptions, like IR or UV)
only the first 7 characters of a word are significant;
common words (like and, are, etc) are ignored
the plural in words should be avoided (use galaxy, not galaxies)

When the Target box is filled, pushing the

||  Find Catalogues

button restricts the choices of catalogues to those having a fair chance to contain objects located in the vicinity of the target – the term vicinity meaning in reality the existence, in the catalogue, of at least one object at a distance of up to 15 arcmin from the actual target position.

When the Target box is filled, pushing the

||  Find Data

button will launch a query to retrieve the actual entries from catalogues satisfying to the selection criteria described above (by free words, or keywords in the Wavelength, Mission or Astronomy domains). For this one-step query, the Output preferences part proposes different output formats, as well as optional computations of the retrieved positions in several astronomical coordinate systems.

3. Browsing Modes

This last way of finding catalogues consists in a few lists of the catalogues ordered in different ways. A Self-Organizing Map of the catalogues, an application of the neural network techniques, offers a last possible view on the set of catalogues.

last update 30 Oct 06:09

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