CatFile Interface V0.03
By F.-X. Pineau, CDS.
Informations about this page
This page is a prototype which provides an access to catalog files originally developed for the
CDS cross-match service
.
Some of the large VizieR catalogs are now integrated in
VizieR
using this pure Java standalone tool (e.g. WISE_PRELIM, SAGE, 2MASS6X, ...).
In a catalog file, all rows have the same byte size and are ordered and indexed using
HEALPix
. For an overview of the structure of a catalog file, see "RowCatFile" in slide 12/18 of
this IVOA talk
, and see slide 7/16 of
this ADASS talk
.
The tool has been designed for large catalogs. It creates a positionally indexed binary file from an ASCII input and provides methods to access the generated file content. Cone search queries can be performed in a few 10's of milliseconds on a file containing more than 2 billion sources.
For more information, contact me at
francois-xavier.pineau@astro.unistra.fr
Thanks to
Thomas Boch
for SAMP ;)
Catalog
Name:
VizieR table:
Description:
Number of rows:
Column selection
ColName
Type
Format
Unit
UCD
Description
Sky area
|
Index
All-sky
Cone search
Center:
Radius:
mas
arcsec
arcmin
deg
Box
Center:
Width:
mas
arcsec
arcmin
deg
Height:
mas
arcsec
arcmin
deg
Angle
:
deg
Zone
α
min
:
α
max
:
δ
min
:
δ
max
:
Healpix cell (ICRS)
Nside:
1
2
4
8
16
32
64
128
256
512
1024
2048
Index:
Healpix MOC
In-line:
File:
Query Center
u-g:
±
g-r:
±
r-i:
±
i-z:
±
nn (nearest neighbour)
k-nn (k-nearest neighbour)
k:
Hypersphere (limit = 10,000 entries)
Radius:
Box (limit = 10,000 entries)
Query Center
B-V:
±
Mv:
±
B-V = magGBp - magG
Mv = meanAbsoluteV
min
max
avg
sigma
B-V
-0.764
14.318
0.940
0.656
Mv
-9.350
39.000
6.391
5.089
Distance are computed on centered-reduced values!
nn (nearest neighbour)
k-nn (k-nearest neighbour)
k:
Hypersphere (limit = 10,000 entries)
Radius:
Box (limit = 10,000 entries)
Filter
Condition
:
Output
No limit
Limit:
Web page
SAMP
TSV ('\t')
CSV (',')
PSV ('|')
SSV (';')
JSON
VOTable
URL:
Catalog entries