extract[/qualifiers] [filename]
Extract a PHA spectrum or a light curve from a binary FITS file. If no filename is given the routine assumes that the event file from which the data is to be extracted is the same as used to extract the current image (see the read/rfits command). This command creates a file with the same name of the FITS file and extension equal to .log and .qdp for the spectrum and lightcurve respectively. These output files are ASCII and can be used as input to programs XSPEC and XRONOS respectively.
The spectrum and lightcurve is extracted only for the region specified in a region file. This region file uses the saoimage region file format. It can be created using saoimage or from ximage using the circ and box commands. The default region file will have the same name as the name of the image/event file, with the extension .reg. If the region file is created within XIMAGE the pixel values are those corresponding to the unrebinned image. If the region file is created within SAOIMAGE the pixel values are those corresponding to a rebinned image. The region given to the 'extract' commands needs to be in original (unrebined) pixels.
If the qualifier /detect is used then the output from a previous run of detect is used to generate a set of hardness/softness ratios for the detected sources.
If /detect is not given, then extract will automatically generate a spectral file that can be read by the psf command, so as to make an energy dependent psf for the source in question.
Specify the channel, n, to be used to generate hardness and softness ratios. The defaults are currently set for ROSAT. To be used together with /c2, /c3, /c4.
Specify the channel, n, to be used to generate hardness and softness ratios. The defaults are currently set for ROSAT. To be used together with /c1, /c3, /c4.
Specify the channel, n, to be used to generate hardness and softness ratios. The defaults are currently set for ROSAT. To be used together with /c2, /c3, /c4.
Specify the channel, n, to be used to generate hardness and softness ratios. The defaults are currently set for ROSAT. To be used together with /c1, /c2, /c3.
Use the positions from a previous run of detect and generate the hardness and softness ratios for each source
The name of the output file with the HR and SR data. The default is the input filename.col. Use /plot to plot a color-color diagram.
Name of the input event file.
Write a spectral file in ASCII format. This file can be converted to xspec format using MKPHA.
Plot a color-color diagram for all the detected sources.
Write a timing file in QDP format. This file is written by default; use none to avoid it being written.
Enter an SAOIMAGE style region file name. If not specified the regionfile name is equal to the events file .reg.
Enter a XRONOS style timing window file.
Specifies the minimum of a range of pha channels to be used when constructing a light curve.
Specifies the maximum of a range of pha channels to be used when constructing a light curve.
Calculate a statistical variability test for detected sources. Values greater than 100 are porbably variable.
When making a color-color diagram it will default to use the PI (pulse invariant) channel. The energy qualifier will use the PHA column instead.
It creates an ASCII pha file which name is telescope_detector.psf, used automatically by the command 'psf'. In the case of the ROSAT PSPC the ASCII pha file is rosat_pspc.psf.
Examples:
extract/reg=agn.reg rp200123.fits ! Extract a spectrum from the rosat
! style fits file
extract/detect/plot ! plot a color-color diagram for
! all the detected sources