SPREAD

Description :  This is the final step in the reduction process. This task will create a simple text file with the instructions to copy the reduced [OTZF] images and the calibration images (dome flats, sky flats, and bias) to the CSP database.

Parameters for "spread"

                    An epar to the task spread will look like this:



SPREAD parameters



               The parameter "SNdir" and "caldir" specify the directory where you want to place the SN images and the calibration images, respectively.
These parameter must take the values /csp1/opt_phot/ and /csp1/opt_phot/calibrations/.

You must set the parameter "opt_ir" to "SDSS".

The "filter" parameter is the image header keyword contaning the filter IDs and the "filterid" specifies the filter IDs. If the observer followed the instructions you should use the option "u g r i B V". If not, check the headers and modify this parameters accordingly.

The "aperture" parameter is the image header keyword that specifies the slit size. The "apertureid" parameter is used to specify the value of "aperture" that corresponds to the open position (no slit). None of these parameters are relevant for the Swope teslescope and could be left blank.

The "date" and the "obstime" parameter are the image header keywords that specify the UT date of observation and the UT time, respectively.

The "instrument" parameter allows you to specify the name of the instrument employed. You can only enter the official CSP names. The "tel" parameter specifies the telescope image header keyword.

The "ra", "dec", and "epoch" parameters specify the right ascension declination, and equinox header keywords. This information will be used to find the name of the supernova in the snphot$sn.coo catalogue file. The value specified in the "tolerance" parameter will be used to match the image coordinates with those of the catalogue.


Execution : This task will search for the the name of the supernova in the snphot$sn.coo catalogue file. The value specified in the "tolerance" parameter will be used to match the image coordinates with those of the catalogue. If the SN is not in the catalogue, start by editing the snphot$sn.coo file. The first column specifies the supernova name; the next two columns have precise equatorial coordinates (2000.0) for each supernova.

If the object is already in the supernova list defined in the parameter "sn_coo", "spread" will find it according to the header coordinates ("ra", "dec", and "epoch") and a tolerance in arcmin that you can specify in the parameter "tolerance" and propose you a name for every image. If the image is not found in the supernova list "spread" will assign it the "nomatch" flag. If this happens you asnwer "no" when prompted to accept this. You will have to add the new SN to the supernova list (snphot$sn.coo in the example above).

Once you have all the SNe properly identified you can asnwer "yes" when prompted. The task will create one subdirectory per SN in the CSP database (whose location is specified with the "dir" parameter). If the subdirectory already exists this operation will be skipped. The task will then write a simple text file named "spread" which you can edit (in general it shouldn't be necessary).

The file "spread" is an IRAF script which contains a series of "imcopy" commands (one image per line) where the output image has been named after the SN name, the filter, a correlative number in case that more than one SN/filter combination was obtained, the telescope, the instrument, and the local date of observation. The calibration images (flats and bias) have been also added to the file "spread". You must execute this script by typing

cl < spread
This command will write the SN and calibration images to the CSP database.


Other Tasks:    -    chkhead    -    headers    -    ccd40    -    spread
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