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Past News Items
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This page provides an archive of past Calibration News items. For general calibration information and recent news, see the Calibration Information page.

  • Erratum in PCARMF V3.3 distributed with FTOOLS 4.1 - Aug 29, 1998
  • Calibration updates accompanying the release of FTOOLS 4.1 - May 8, 1998
  • Calibration updates accompanying the release of FTOOLS 4.0 - June 17, 1997
  • New HEXTE response matrices - April 3rd, 1997
  • Calibration updates accompanying the March 3rd RXTE Ftools - March 3rd, 1997
  • HEXTE response matrices and sample HEXTE Crab spectra - May 7th, 1996
  • Calibration updates accompanying the May 6th RXTE Ftools - May 7th, 1996
  • New HEXTE response matrices - December 13th, 1996
  • Calibration updates accompanying Ftools 3.6 - October 22nd, 1996
  • PCA and HEXTE responses for AO-2 proposal simulations - May 15th, 1996
  • HEXTE response matrices and sample HEXTE Crab spectra - May 7th, 1996
  • Calibration updates accompanying the May 6th RXTE Ftools - May 7th, 1996
  • Three new PCA calibration items - April 17th, 1996
  • New PCA EDS gain and offset calibration file - March 1st, 1996
  • Collimator response and channel-to-energy conversion files - February 20th, 1996
  • First post-launch PCA calibration files - January 31st, 1996
  • Preliminary ephemeris for satellite orbit - January 11th, 1996
  • HEASARC CALDB - What's New (general - not just RXTE)
  • RXTE calibration files in the HEASARC CALDB


    Erratum in PCARMF V3.3 distributed with FTOOLS 4.1

    Aug 29, 1998: PCARMF V3.3 (included in FTOOLS v4.1) contains a bug in which the time dependence of the gain is not computed if the channel-to-energy parameters are read from the FITS calibration file. Hence the constructed matrices are equivalent to those for April 14, 1996. However, the gain drift is computed correctly if the channel-to-energy parameters are read from an ascii file. Users may utilize the ascii input by doing the following:

    1. use the pset command to set the pcarmf hidden parameter "nofits" to a value of 1.
    2. Download the Ascii file, and call it e.g. PCA.energy2chan.v3.0.txt
    3. run pcarsp using
      > pcarsp -e PCA.energy2chan.v3.0.txt

    This bug will be corrected in the next release of the FTOOLS, expected in November, 1998.


    Calibration Updates Accompanying the Release of FTOOLS 4.1

    May 8, 1998: The FTOOLS 4.1 package contains updates for the response matrix generator for the PCA. This is accompanied by a new channel to energy matrix in the calibration data base.

    FTOOLS 4.1 also includes hxtdead, a new tool for computing dead time for HEXTE spectra and light curves. This single tool replaces hxtdeadlc and hxtdeadpha. HXTDEAD corrects both archive and event modes, allows for binsizes larger than the rocking interval, and interpolates for small shortfalls in the housekeeping data. Two calibration files accompany HXTDEAD. These may be found via ftp to legacy.gsfc.nasa.gov in the directory

      /caldb/data/xte/hexte/bcf/deadtime/hxtdead_97jul2_pw[ab].fits

    where the "a" file applies to cluster 0 (or "A") and the "b" file applies to cluster 1 (or "B").


    Calibration Updates Accompanying the Release of FTOOLS 4.0

    June 17, 1997: The FTOOLS 4.0 package is designed to work with new PCA calibration files, described below. Previous versions of these files will not work with FTOOLS 4.0. To get the new calibration data, you may either:

    • update or install CALDB on your site (if you will also being using ASCA and ROSAT calibration files, you must choose this option)

    Once you have installed the updated whole or RXTE-only CALDB, tools such as pcarsp will automatically use this data when run. Further details about the refined calibration data and programs follows:

    • New version of pcarsp: A number of changes have been made for pcarsp v2.31:

      1. Three command line options have been added to override some default settings:

        • The default naming scheme for the final .rsp file has been altered for cases in which not all detectors are used, but are added together. The default name now explicitly lists the PCU's in such cases. The "pca" designation is reserved for when all 5 PCU's are added. The user may override the default name given to the final .rsp file using the -n command line input.

        • The date of the observation is now taken from the header of the input pha file. The user may override this date using the -d command line input.

        • Using the -e option, the user may now specify an energy-to-channel calibration file which is resident on a local disk rather than having it fetched from the calibration database (e.g. caldb).

      2. The option for using the crab-fixing efficiencies in pcarmf have been removed. In v2.1.2 of pcarmf, this now requires the user to supply his/her own file with modified areas. We now consider this an expert feature. Interested users should contact the GOF or the PCA team.

      3. When used with pcarmf v2.1.2, users may now create a matrix for the propane layer.

      4. Lower case is now accepted when specifying the layer anodes.

      5. Bug fixes include better cleaning up of the unnecessary files, allowing the calls to pcarmf, marfrmf, xpcaarf and gcorrmf to overwrite existing output files, and proper calling of gcorrmf when pcarsp runs pcagainset.

    • New version of pcarmf (v2.1.2): This version of pcarmf includes a number of changes and enhancements. Note that it should be used with the calibration file pca_e2c_e03v031.fits(see below):

      1. The supported energy-to-channel model is now "3". This model first translates the energy of the photon into the number of secondary electrons, and then allows a quadratic fit for channel number as a function of number of electrons. The x-axis (number of electrons) is renormalized to be approximately the energy for convenience for plotting inside xspec.

      2. Propane matrices may now be created, and are individually generated for each PCU to account for the different PCU gains. The normalization of propane response to xenon response is unexpected (i.e. not 1). Users are advised to let the normalization of the propane layer float relative to other layers for the time being. 3) The default areas have been removed for the crab-fixing efficiency adjustments. Hence, to utilize the scale_hack parameter, the user must now supply his/her own file (using the scale_file parameter) giving the area adjustments.

      3. Parameters used to calculate the response matrix are now written as HISTORY keywords to the extension header. These include many of the hidden pcarmf parameters.

    • New energy-to-channel file for pcarmf: the file pca_e2c_e03v031.fits includes new energy-to-channel coefficients for all detectors, all layers, and all epochs. It supports the new features and e2c_model=3 used in pcarmf v2.1.2 (ftools v4.0). The file, however, also includes the e2c_model=2 extensions from the previous version, pca_e2c_e03v02.fits. This is to provide backwards compatibility with pcarmf v2.0.2 (in ftools v3.6.1). NB - the e2c_model=2 values should not be used with pcarmf v2.1.2 (in ftools v4.0). Likewise, the e2c_model=3 values should not be used with pcarmf v2.0.2.

    • In addition:

      1. Matrices for lld=63 (i.e. all layers) are now created as the sum of lld=3 + 12 + 48 (i.e. LR1 + LR2 + LR3). In addition, matrices for the half layers (e.g. L1 or R1) use the parameters for the entire layer (e.g. LR1).

      2. When used with pcarmf v2.1.2, propane matrices may now be created, and are individually generated for each PCU to account for the different PCU gains. The normalization of propane response to xenon response is unexpected (i.e. not 1). Users are advised to let the normalization of the propane layer float relative to other layers for the time being.

      3. No energy-to-channel conversion parameters exist for PCU's 3 or 4 for gain epoch #2 (March 21 - April 15, 1996). These PCU's were mostly off during this period, and the PCA team recommends ignoring them. Should a user have a pressing need for matrices for these detectors during this time, contact the RXTE GOF.


    New HEXTE Response Matrices

    April 3rd, 1997: The HEXTE Instrument Team has made available a new set of response matrices. Superseding the previous, November 1996 set, the new matrices provide better fits to the Crab as well as a cosmetic improvement to the channel-to-energy conversion used by xspec for plotting. The matrices are available via anonymous FTP at legacy.gsfc.nasa.gov as the gzipped tar file:

       /xte/calib_data/hexte_97mar20c_resp.tar.gz
    

    The accompanying README file describes the matrices and includes a set of recommendations for using them effectively.


    Calibration Updates Accompanying RXTE Ftools 3.6.1

    March 4th, 1997: The March 4th release of version-3.6.1 of the RXTE Ftools package includes several new PCA calibration files which should be used with the release.