Notes on analyzing XTE data using XSELECT

Reading the data into XSELECT

Because XTE data comes in a rather complex file structure and with non-obvious names it is easiest to start by using XSELECT's ability to make an observation catalog. Start at the top of the data directory tree... 
 
                         **  XSELECT V2.2   **
 
> Enter session name >[xsel] 
 
 Notes: XSELECT set up for      ASCA
 Time keyword is TIME       in units of s
 Default timing binsize =   16.000
 
xsel:ASCA > set miss xte
 
 Notes: XSELECT set up for      XTE
 Time keyword is TIME       in units of s
 Default timing binsize =   16.000
 
xsel:XTE > set instr PCA
 
Setting...
 Energy keyword   = GOOD                   with binning =    1
xsel:XTE-PCA > make obscat
> Enter the Event file dir >[./] 
> Default filter for the catalogue (NONE for none, DEF for default)
 >[DEF] 
Using default selection expression: INSTRUME=='PCA'
 
******************** Observation Catalogue ********************
 
Data Directory is: /Users/kaa/RXTE/P40168/
HK Directory is: /Users/kaa/RXTE/P40168/
 
 
        INSTRUME    OBSERVER    OBJECT      DATAMODE    DATE-OBS    TIME-OBS    HDUCLAS2
      1 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-20T 15:23:44    TOTAL
      2 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-20T 23:45:20    TOTAL
      3 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-21T 23:41:36    TOTAL
      4 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-22T 12:05:36    TOTAL
      5 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-22T 20:08:32    TOTAL
      6 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-23T 21:50:24    TOTAL
      7 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-23T 23:32:32    TOTAL
      8 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-24T 15:10:24    TOTAL
      9 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-25T 07:44:32    TOTAL
     10 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-25T 09:20:32    TOTAL
     11 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-25T 21:41:36    TOTAL
     12 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-26T 09:14:24    TOTAL
     13 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-26T 23:38:56    TOTAL
     14 PCA         KEITH ALEC  CYGNUS-A    Standard2f  2000-05-27T 18:09:04    TOTAL
The catalog lists all the Standard2f data available. Standard2f is the only PCA mode supported by XSELECT. We read in files we want using the choose command... 
xsel:XTE-PCA > choose 1-2
 
   Setting datamode to Standard2f
 
Got the minimum time resolution of the chosen data:  0.16000E+02,
 
Number of files read in:    2
 
Files currently in use:
 
   1   FS4a_c01f0be-c020093
   2   FS4a_c026650-c027023.gz
Note that one file is in gzipped format. Uncompresses will be handled automatically however it is a good idea if the files are large to uncompress them before entering XSELECT since otherwise they will be uncompressed each time they are used within XSELECT.

Filtering on PCU, layer, and anode

The PCA has 5 individual detectors, each with three layers and two anode sides. Products can be accumulated for subsets of the whole instrument using filter detector. Suppose we are interested in only PCU1 but all layers and both sides.. 
xsel:XTE-PCA-STANDARD2F > filt det "0** 2**"
Detectors just selected (- means detector will be removed)...
X1LSpecPcu0
X1RSpecPcu0
X2LSpecPcu0
X2RSpecPcu0
X3LSpecPcu0
X3RSpecPcu0
X1LSpecPcu2
X1RSpecPcu2
X2LSpecPcu2
X2RSpecPcu2
X3LSpecPcu2
X3RSpecPcu2
Some care should be exercised when selecting PCUs because the number of PCUs in use can change during an observation. Note that if the detector string starts with a wildcard (*), ie all PCUs are selected, then the string must be enclosed in double quotes.

Extracting light curves and spectra

To make a light curve and spectrum of the selected detectors... 
xsel:XTE-PCA-STANDARD2F > extr all
 
Running SAEXTRCT version 4.2d
==============================================
 
Processing GTIORFILE
/Users/kaa/RXTE/P40168//40168-01-01-00/pca/FS4a_c01f0be-c020093+2
 
Processing GTIORFILE
/Users/kaa/RXTE/P40168//40168-01-01-07/pca/FS4a_c026650-c027023.gz+2


....... Much additional output .......


------------------------------------------
Column that is being output is:     Combination of many columns
Total Counts for FITS Light Curve:             561940.00
Total Time for FITS Light Curve:                 6544.000000
Total Counts/Time for FITS Light Curve:            85.871027
 
Writing out Light Curve FITS file
 
Creating output light curve file:
xsel_tmpfillc.fits
Wrote Light Curve
 
 
Writing out GTI for Light Curve FITS file
 
Wrote out GTI extension.
Closing Light Curve.
 
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Total number of columns output is:                       1
 
------------------------------------------
Column that is being output is:     Combination of many columns
Total Counts for FITS Spectrum:                561940.00
Total Time for FITS Spectrum:                    6544.000000
Total Counts/Time for FITS Spectrum:               85.871027
 
Writing out Spectrum FITS file
 
Creating output spectral file:
xsel_tmpfilsp.fits
 
Writing out GTI for Spectrum FITS file
Wrote Spectrum FITS file
Closing Spectrum.

 
Everything is finished.
Cleaning up memory and exiting.
The light curve and spectrum can be saved using the save curve and save spectrum commands.

Automated response generation

The save spec resp=yes option for XTE PCA data simply runs the FTOOL pcarsp. This will produce the correct response provided that the source is at the center of the collimator.

A service of the Laboratory for High Energy Astrophysics (LHEA) at NASA's GSFC
Responsible NASA Official: Phil Newman
Curator: Keith Arnaud

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This file was last modified on Wednesday, 14-Mar-2012 17:22:53 EDT