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XTE Patch to FTOOLS v4.1

This patch updates the XTE related tools to v4.1.1 and provides

  • A dramatic improvement to the PCA background models, which will have a profound impact in your ability to analyze data from faint sources, and;

  • Associated improvements to XTEFILT, and fixes to bugs in FXBARY, RDDESCR, and MKGTIF.

If you have RXTE data obtained in Epoch 3 (April 15, 1996 - present) for which the source count rate is less than 40 ct/sec/PCU, you should reanalyze your data using the new "L7" background model, contained in this patch, which takes into account various particle monitors and the SAA history!

The new model is described in detail on the PCA pages. Briefly, characteristics of the L7-240 model include:
  • Excess variance of <0.1 ct/sec (2-10 keV; PCUs 0-3). The systematic error in the 2-10 keV band is now ~0.1 times the 1-sigma CXB fluctuation.
  • Excess variance of <0.1 ct/sec (10-20 keV),
  • Reliable spectral subtraction below 24 keV for energies where net signal is >0.01 ct/sec/keV
Efforts are currently underway to construct a model that extends to brighter sources, and application of the models to epochs 1 and 2.

This patch also fixes bugs that were reported in the following RXTE tools from the FTOOLS version 4.1 release: fxbary, rddescr, mkgitf. The tool rddescr is used by pcarsp to generate response matrices.

If you have had failures when attempting to generate response matrices or barycenter correct data under FTOOLS 4.1, get and install this patch.

Additionally, xtefilt and its associated programs have been updated to include information about electron contamination and time since an SAA passage in the filter files. Filtering based on these quantities should result in substantially cleaner data sets with better signal-to-noise values.

Instructions on installing the patch and all associated files can be found on the anonymous ftp area at ftp://legacy.gsfc.nasa.gov/xte/software/xte_update The README and release notes describing significant changes to the analysis tools are also includedm. For detailed instructions about how to use the new background model and software, please see the pcabackest recipe.

We expect that the new background models will encourage a flurry of publications on RXTE faint source observations. As always, if you have an article based on RXTE data accepted for publication, please drop us a note so we may include it on our web pages.

Notes on Previous XTE Software Releases (including FTOOLS v4.1).


If you have a question about RXTE, please send email to one of our help desks.

This page is maintained by the RXTE GOF and was last modified on Tuesday, 14-Sep-1999 13:46:03 EDT.