QUERYDSS
Name
QueryDSS
Purpose
Query the digital sky survey (DSS) on-line at the STSCI (or ESO) server
Explanation
The script can query the DSS survey and retrieve an image and FITS
header either from the the Space Telescope Science Institute (STScI) or
European Space Observatory (ESO) servers.
See http://archive.eso.org/dss/dss and/or
http://archive.stsci.edu/dss/index.html for details.
Calling Sequence
QueryDSS, targetname_or_coords, Im, Hdr, [IMSIZE= , /ESO, Outfile= ]
Inputs
TARGETNAME_OR_COORDS - Either a scalar string giving a target name,
(with J2000 coordinates determined by SIMBAD (default) or NED), or
a 2-element numeric vector giving the J2000 right ascension in
*degrees* and the target declination in degrees.
Optional Inputs
None
OPTIONAL KEYWORD PARAMETERS:
ImSize - Numeric scalar giving size of the image to be retrieved in
arcminutes. Default is 10 arcminute.
/ESO - Use the ESO server for image retrieval. Default is to use
the STScI server
/NED - Query the Nasa Extragalactic Database (NED) for the
target's coordinates. The default is to use Simbad for
the target search.
OUTPUT - scalar string specifying name of output FITS file.
If set, then the output IDL variables are not used.
/STSCI - obsolete keyword, now does nothing, since STSCI is the default
Server.
SURVEY - Scalar string specifying which survey to retrieve.
Possible values are
'1' - First generation (red), this is the default
'2b' - Second generation blue
'2r' - Second generation red
'2i' - Second generation near-infrared
Note that 2nd generation images may not be available for all regions
of the sky. Also note that the first two letters of the 'REGION'
keyword in the FITS header gives the bandpass 'XP' - Red IIIaF,
'XJ' - Blue IIIaJ, 'XF' - Near-IR IVN
/VERBOSE - If set, then the query sent to the DSS server is displayed
Outputs
Im - The image returned by the server. If there is an error, this
contains a single 0.
Hdr - The FITS header of the image. Empty string in case of errors.
If the OutFile keyword is set then no outputs are returned (only the
file is written).
Side Effects
If Im and Hdr exist in advance, they are overwritten.
Restrictions
Relies on a working network connection.
Procedure
Construct a query-url, call WEBGET() and sort out the server's
answer.
Example
Retrieve an 10' image surrounding the ultracompact HII region
G45.45+0.06. Obtain the 2nd generation blue image.
IDL> QueryDSS, 'GAL045.45+00.06', image, header, survey = '2b'
IDL> tvscl, image
IDL> hprint, header
IDL> writefits,'dss_image.fits', image, header
Note that the coordinates could have been specified directly, rather than
giving the target name.
IDL> QueryDSS, [288.587, 11.1510], image, header,survey='2b'
To write a file directly to disk, use the OutFile keyword
IDL> QueryDSS, [288.587, 11.1510], survey='2b', out='gal045_2b.fits'
Procedures Called
QUERYSIMBAD, WEBGET()
Modification History
Written by M. Feldt, Heidelberg, Oct 2001 <mfeldt@mpia.de>
Option to supply target name instead of coords W. Landsman Aug. 2002
Added OUTFILE, /NED keywords W. Landsman April 2003
Don't abort on Simbad failure W. Landsman/J. Brauher June 2003
Added /VERBOSE keyword W. Landsman Jan 2009
Make /STScI server the default W. Landsman June 2010
Fix OUTPUT option W. Landsman June 2010