QUERY_IRSA_CAT
Name
QUERY_IRSA_CAT
Purpose
Query a catalog in the NASA/IPAC Infrared Science Archive (IRSA)
database by position or resolvable target name.
Explanation
Uses the IDL SOCKET command to provide a query of a catalog
in the IRSA (http://irsa.ipac.caltech.edu/) database over the Web and
return results in an IDL structure. If outfile is set, it saves
the query as an IPAC table file. This can be slow for large query
results, so only write a file if needed.
Calling Sequence
info = query_irsa_cat(targetname_or_coords, [catalog=catalog,
radius=radius, radunits=radunits, outfile=outfile,
change_null=change_null, /DEBUG])
Inputs
TARGETNAME_OR_COORDS - Either a string giving a resolvable target
name (with J2000 coordinates determined by NED or SIMBAD), or a
2-element numeric vector giving the J2000 right ascension
and declination, both in degrees.
Optional Input
CATALOG - string giving the identifier of the IRSA catalog to be
searched. The complete list of catalogs and identifier strings is available in
XML format at:
http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-scan?mode=xml
or as an IPAC Table (ascii) at:
http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-scan?mode=ascii
In the table, the identifier string is in the "catname" column.
If this keyword is omitted, the program will query the 2MASS point
source catalog.
Examples of current IRSA catalogs include:
'wise_allsky_4band_p3as_psd' - WISE All-Sky Source Catalog
'fp_psc' - 2MASS Point Source Catalog
'iraspsc' - IRAS Point Source Catalog v2.1 (PSC)
'irasfsc' - IRAS Faint Source Catalog v2.0
'cosmos_ib_phot' - COSMOS Intermediate and Broad Band Photometry Catalog 2008
'akari_irc' - Akari/IRC Point Source Catalogue
RADIUS - scalar input of the radius of the search. By default it
has a value of 60 arcsec. IRSA
catalogs have maximum allowable search radii. These are listed on the corresponding
web interface page for the catalog search, or in the nph-scan return table in the
"coneradius" column.
RADUNITS - string giving the units of the radius. By default it is 'arcsec'.
OUTFILE - if present, the search results are written to a file with this name.
CHANGE_NULL - a numeric value (input as integer) to put in the structure if the table uses a string for nulls. Default is -9999.
DEBUG - /DEBUG provides some additional output.
Outputs
info - Anonymous IDL structure containing information on the catalog. The structure
tag names are taken from the catalog column names. If no objects were found in
the catalog, the structure values will be empty or zero. If any input parameter
(e.g. catalog name) is invalid, the structure will have no
content fields other than info.CREATED.
If the query fails or is invalid, the function returns a value of -1.
Examples
(1) Plot a histogram of the J magnitudes of all 2MASS
point sources within 10 arcminutes of the center of the
globular cluster M13. Save the IPAC table.
IDL> info = query_irsa_cat('m13',radius=10,radunits='arcmin',outfile='save.tbl')
IDL> help,/struct,info
IDL> plothist,info.j_m,xran=[10,20]
(2) Find the position of the faintest IRAS 60 micron
source within 1 degree of central position of the
COSMOS survey (10h00m28.6s +02d12m21.0s in J2000)
IDL> info = query_irsa_cat([150.11917,2.205833], catalog='irasfsc', radius=1, radunits='deg')
IDL> help,/struct,info
IDL> idx = where(info.fnu_60 eq min(info.fnu_60))
IDL> print, (info.ra)[idx], (info.dec)[idx]
Procedures Used
READ_IPAC_VAR comes with query_irsa_cat.pro
WEBGET(), VALID_NUM from IDLastro
Notes
The program writes an output IPAC table file only if the
OUTFILE keyword is set.
Modification History
Adapted from queryvizier.pro - H. Teplitz, IPAC September 2010
Removed requirement of writing/reading IPAC table file -
T. Brooke, IPAC May 2011
Longer timeout for webget, added change_null - TYB June 2013