extract 300-extract - extract light curve, image or spectrum extract light curve, image or spectrum

Extract a light curve, image, or spectrum (or all three) or an event list. Extract is the new name for the old bin command. Bin still works for the nonce.

It assumes that there is a GTI extension, called STDGTI in the same fits file which stores the event data. It accepts timing data in three forms, ASCII or FITS GTI form, and Xronos window format. It also accepts SAOIMAGE format region descriptor files, which are concatenated into one file called xsel_region.xsl, and fed to the extractor program.

If sisclean has been run, with method 1, then the cleaned events list (stored in xsel_in_events.xsl) will be used. To clear this use clear sisclean.

If select hk or select mkf have been run, the results will be will be applied automatically. To clear this use clear hksel, or clear mkfsel.

If a timing selection has been made using plot curve, this too will be applied automatically.

The various binsizes, etc, are inherited from the set command. Some of them can also be changed on the fly, by entering hidden parameters, but these values only apply to this invocation of extract.

xsel > extract <bin_what> [binsize_t] [pharebin_t] [xybinsize_t] [phalcut_t] [phahcut_t]

Binned spectra, images and lightcurves can be plotted with the PLOT command.

Examples:

Example 1:

xsel > extract ``CURVE EVENT"

Produces a light curve, and also a filtered event list. To use this filtered event list for the next run of extract, say

xsel > save event my_evtlist.fits yes

You can also save the event list, and re-enter it using the read command.

Extract 2:

xsel > extract ALL

this is equivalent to

xsel > extract ``CURVE IMAGE SPECTRUM"

Example 3:

xsel > extract ``CURVE SPECT" bins = 30 pharebin = 4

Extracts a light curve and a spectrum, and temporarily resets the binsize and pharebinning factors.

Parameters:

 NAME          TYPE    PROMPT                                  DEFAULT
 =====================================================================
 bin_what      STRING  Give parameter to be binned
 [binsize_t]   REAL    Give bin size in seconds              -1.0
 [pharebin_t]  INTEGER Temporary Bin size for PHA            -1
 [xybinsize_t] INTEGER Rebinning factor for the image        -1
 [phalcut_t]   INTEGER Temporary Lower cutoff for PHA        -1
 [phahcut_t]   INTEGER Temporary Upper cutoff for PHA        -1
 [exposure]    DOUBLE  Threshold exposure value for the     0.99
                       light curve