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We are pleased to announce the release of FTOOLS v4.0. In this message, we summarize:

  1. How to obtain FTOOLS v4.0
  2. Impact on ASCA users

1. How to obtain FTOOLS v4.0

FTOOLS v4.0 has been released, and can be obtained from the FTOOLS web-page at:

This is where the most up to date FTOOLS information is available,i including notices of the FTOOLS releases, online HTML versions of FTOOLS documentation, and the continually updated FAQ. Users should always check here first for answers to questions.

Any problems installing FTOOLS should be reported to: Feedback form.

Any problems using FTOOLS for ASCA data analysis should be reported to the ftoolshelp address above or to:

Feedback form.

If the problem relates to the scientific contents of the FTOOLS, the latter address is more appropriate.

2. Impact on ASCA users

2a. New/updated tasks in v4.0

This tool now follows the channel numbering convention of the input file.

Both SIS and GIS event files are numbered from channel 0, and therefore the extactor originally creates the spectral files that also start with channel 0. However, old versions of bnpha (which is run by default when extracting SIS spectra in xselect) used numbers starting with channel 1 in the output files. With this new version, rbnpha will respect the channel numbering convention of the input file, which solves several problems such as encountered in adding GIS-2 and GIS-3 spectra taken while GIS-3 was suffering the bit problem.

IMPORTANT: You need xspec 9.02 or later, or else there will be a suprious 1-channel shift in the SIS spectral analysis. If you use your own spectral analysis package, please contact ascahelp to make sure your software interprets the latest SIS response matrices correctly.

Ascascreen now uses ad*.unf files as default input; to use raw ft*.fits files, specify ascascreen -e fits. Ascascreen now uses a more sensible threshold (4 times readout cycle) for SIS t_dy_nt and t_saaCOR); it will also have different region files for removing the background ring for spread discriminator off data.

The problem in previous versions, where the standard region selection for GIS 64x64 spatial resolution mode failed, has been fixed.

Xselect / extractor
The program that is run by the xselect extract or bin command has been extensively overhauled and is available as an ftool called extractor. See fhelp extractor for details. A number of bugs have been fixed in the region filtering. All regions with the exception of circles were one pixel off in both dimensions. In addition, the circle region did not always work correctly. Region filtering should now work for all sizes of regions. Note that a good way to check that the region filtering is correct is to extract a filtered image, read it and the region file into SAOimage or SAOtng, and check that all pixels with any part in the region were selected. Extractor now uses dynamic memory so there is no (theoretical) limit to the size of images that can be extracted. In particular, the problems extracting ROSAT images at binning factors less than 15 have been fixed.

Xselect now supports SAX LECS and MECS.

The new version contains
  • New FITS keywords that allow xspec to handle matrices that begin with channel 0
  • Correct treatment of the event threshold for PI spectra.

    IMPORTANT NOTE If you previously fudged FITS keywords of your spectral file(s) to 'fool' sisrmg into creating the correct response files, you should delete these spectral files. The new version will only work correctly with unfudged spectra.

  • Gains=0 is now the default (previously -1) for constructing the energy-channel mapping; this will result in slight shifts for various spectral features (some better, some worse). However, fitting results are independent of the gains parameter.
  • A primitive support for data processed with correctrdd

This script combines the source and the background spectra and the response files from different instruments or observations, and takes care of the complex background normalization automatically.

Ghkcurve now intersects the user's input Good Time Interval list with the input housekeeping file's ALLGTI extension, if there is one. The merged GTI list is written in the output file, instead of just copying the gtifile one. The user can now specify which monitor count to read with the new `monitor' parameter, and can say to not use an input GTI with `gtifile=none' (the ALLGTI is still applied). Ghkcurve now writes checksum keywords, applies TIMEZERO keywords, uses the actual first and last times for TSTART and TSTOP, can handle larger GTI arrays, and resets the integration when an SF_LOST HK entry is encountered.

Arf calculation for the GIS has been sped up by using an FFT to convolve the telescope and detector point response functions. A new parameter bkgfile can be used to specify an image to be subtracted from the WMAP before calculating the arf.

Now uses an FFT to convolve the telescope and detector point response functions.

Mekal and Raysmith
These are new ftools that can be used to run the Mewe-Kaastra-Liedahl and Raymond-Smith equilibrium collisional plasma models and build an XSPEC table file. This file can be used to replace the one used by default in XSPEC if a different parameter or energy gridding is required.

This ftool can be used to build test instrument response matrices. The response is assumed to be gaussian with no escape features. A variety of different dependences of resolution with energy or wavelength are available.

This ftool now works.

No longer requires filenames to be < 100 characters.

This new program allows Faint mode data to be corrected for the RDD (residual dark distribution) effects. Please regard this as a beta-test version, in that the calibration of spectral response for RDD-corrected data is still in an early stage. Correctrdd should be run on Faint mode files; although it can also be run on Bright mode files, the effects of doing so are poorly understood; it is expected to be much less effective than running it on Faint mode files. Correctrdd requires RDD map files --- these will be generated on request by the SIS team, although in future we may be able to provide them in CALDB, for example.

This is a beta-test FTOOLS version of the Nagoya University code (ray2areav6_0cal) to ray trace the ASCA mirrors, with enhancements to the gold atomic constants as implemented by GSFC's Keith Gendreau. Since this is the first release, users interested in using this code should make sure that they contact both the ASCA GOF and the ray trace experts of Nagoya University for information on valid parameter values for use with the code and limitations on its use. Users should restrain their enthusiasm to use the code to create non-standard calibrations that slighty improve spectral fits until they have familiarized themselves with the large body of work already performed by Nagoya and the GSFC staff.

2b. A note for users of XTE update v3.6.1

As noted earlier, the new version of rbnpha was included in v3.6.1, however the corresponding update to sisrmg was incomplete, causing a spurious 1 channel shift when analyzed using xspec. If you have gotten around this problem by inserting the TLMIN4 keyword in the response matrix, you need not take any further action.

  1. How to obtain FTOOLS v4.0
  2. Impact on ASCA users

This file was last modified on Wednesday, 07-Apr-2004 11:03:08 EDT
Curator: Michael Arida (SP Sys);
HEASARC Guest Observer Facility
If you have any questions concerning ASCA, visit our Feedback form.

This file was last modified on Wednesday, 07-Apr-2004 11:03:08 EDT

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