- Examine the filter file:
In general, the filter file tells you the status of the satellite and its instruments during your observation and can be used to identify periods of good data. In particular, the column NUM_PCU_ON will tell you how many PCUs were on during the observation. To see which if PCUs were off, plot the columns:
PCU0_ON
PCU1_ON
PCU2_ON
PCU3_ON
PCU4_ON
NUM_PCU_ON
or the columns containing the count rates from the individual PCUs:
evXEgood_PCU0
evXEgood_PCU1
evXEgood_PCU2
evXEgood_PCU3
evXEgood_PCU4
- Create GTI files with maketime:
If you find, for example, that your observation has periods when all five PCUs are on and periods when only PCUs 0-2 are on, you can generate GTI files containing these periods using maketime:
kaah[21]% maketime
Name of FITS file and [ext#][] realtime_go.xfl
Name of output FITS file[] pcus_01234.gti
Selection Expression[] NUM_PCU_ON.eq.5
Column containing HK parameter names[NAME]
Column containing HK parameter values[VALUE]
Column containing HK parameter times[TIME] Time
Flag, yes if HK format is compact[yes] no
and
kaah[21]% maketime
Name of FITS file and [ext#][realtime_go.xfl]
Name of output FITS file[pcus_01234.gti] pcus_012.gti
Selection Expression[NUM_PCU_ON.eq.5] NUM_PCU_ON.eq.3
Column containing HK parameter names[NAME]
Column containing HK parameter values[VALUE]
Column containing HK parameter times[Time]
Flag, yes if HK format is compact[no]
- Create column selection files:
If extracting Standard-2 data then you should create column selection files corresponding to the PCUs and anodes you want. See the recipe Selecting PCA Data by PCU, Layer and Anode for more details. [Note, however, that this is not strictly necessary if you use GTI files to identify the 3-PCU and 5-PCU periods. This is because saextrct does not accumulate exposure from columns with no data in them.]
- Extract the source and background spectra and light curves, make the response matrices
: The recipe Reduction and Analysis of PCA Spectra explains how. Each 3-PCU, 4-PCU and 5-PCU spectrum and light curve should have a corresponding background file. And you should make responses for 3-PCU, 4-PCU and 5-PCUs.