SAS watchout page


SAS watchout page

In this page some issues concerning SAS and XMM-Newton data analysis are reported, along with recommended workarounds and/or solutions, and useful tricks and tips.

Many of the items below are extracted from the HelpDesk questions database, and frequently updated.
Users are invited to search this database, especially the SAS related folders, before contacting the XMM-Newton HelpDesk.

In addition, users should also check release notes of latest SAS patches, available on the SAS News web page, as a new patch might have been released already fixing the encountered problem.

If you encounter a new issue in analyzing XMM-Newton data with the SAS software, please try to give as much information as needed to reproduce your problem, including the following details:

  • Output of the sasversion command,
  • Observation identifier,
  • Information about the CCF in use.

Current SAS Version related issues

SAS 16.0.0

  • After having patched the original SAS 16.0 version, trying to run the Perl task epchain, produces the error message
    epchain: Command not found
    while any other SAS task is found.
    How can I fix the problem? -- Answer
  • After installing SAS 16.0.0 on macOS Sierra (Mac OS X 10.12*), running any SAS task, e.g. epproc, produces the error message
    dyld: Library not loaded...
    How can I fix the problem? -- Answer
  • Running xmmextractor on Mac OS X 10.11.6 El Capitan, I get the following error message:
    Can't load '$SAS_DIR/lib/perl5/darwin-2level/auto/XML/LibXML/LibXML.bundle' for module XML::LibXML: dlopen($SAS_DIR/lib/perl5/darwin-2level/auto/XML/LibXML/LibXML.bundle, 1): Library not loaded: /opt/local/lib/libiconv.2.dylib
      Referenced from: $SAS_DIR/lib/perl5/darwin-2level/auto/XML/LibXML/LibXML.bundle
      Reason: Incompatible library version: LibXML.bundle requires version 8.0.0 or later,
      but libiconv.2.dylib provides version 7.0.0 at /Users/user/perl5/perlbrew/perls/perl-5.22.3/lib/5.22.3/darwin-2level/ line 197.
      at $SAS_DIR/lib/perl5/darwin-2level/XML/ line 156.
      BEGIN failed--compilation aborted at $SAS_DIR/lib/perl5/darwin-2level/XML/ line 156.
      Compilation failed in require at $SAS_DIR/lib/perl5/ line 5.
      BEGIN failed--compilation aborted at $SAS_DIR/lib/perl5/ line 5.
      Compilation failed in require at $SAS_DIR/bin/xmmextractor line 206.

    How can I fix this problem? -- Answer
  • After the installation of SAS 16.0.0 on MacOS X Yosemite or El Capitan, SAS initialisation produces the following error message:
    dyld: Symbol not found: __cg_png_create_info_struct
      Referenced from: /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO
      Expected in: $SAS_DIR/libextra/libPng.dylib
      in /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO
    Trace/BPT trap: 5

    How can I fix this problem? -- Answer

SAS 15.0.1

  • I cannot run SAS on macOS Sierra. What can I do? -- Answer
  • My observation has been made in EPIC multi-pointing mode, how can I process it correctly ? -- Answer

SAS 15.0.0

  • Can I use a box region to extract EPIC-pn Timing or Burst mode spectra? -- Answer
  • I am running the SAS 15.0.0 on a Linux RHEL 6.X machine and xmmextractor is crashing.
    How can I fix this problem? -- Answer
  • When the task emosaic_prep is ran, it gives the following error:
    Cannot exec "preqgti": No such file or directory at...
    How to fix this problem? -- Answer
  • Why do certain tasks end with a fatal error including: UnknownAlgoId? -- Answer
  • dyld: Library not loaded... error with SAS installed on Mac OS X El Capitan -- Answer

Evergreen tips and tricks

  • How can I correct OM Grism Spectra for Time Sensitivity Degradation? -- Answer
  • Caution when analysing EPIC Timing Mode spectra extracted from very narrow regions -- Answer
  • Caution when analysing EPIC spectra extracted from annular source regions -- Answer
  • Is the RGS-pn rectification correction valid for data processed with SAS 14? -- Answer
  • Why do I have to correct EPIC-pn Timing Mode exposures for X-ray Loading (only necessary for observations performed until 23 May 2012)? -- Answer
  • Should I use evselect or epiclcorr for obtaining EPIC light curves? -- Answer
  • These long parameter names are really annoying ... -- Answer
  • How do I compare two Calibration Index Files? -- Answer
  • Can I generate EPIC response matrices with all types of spectral binning? -- Answer
  • Where can I find canned EPIC response matrices? -- Answer
  • Can I perform the barycentric correction on OM data in Fast Mode? -- Answer
  • How can I convert from OM count rates to fluxes? An update -- Answer
  • Dealing with MOS1 data in Timing Mode: I heard that one column in MOS1 Timing Mode is affected by "high offset", can I still analyze the data? -- Answer


  • Why does it take so long to produce an ODF? -- Answer

PPS products

  • Why do I get problems ingesting RGS (pipeline) spectra into XSPEC V12.x and how can I solve this? -- Answers
  • How do I know which CCF were used to reduce my event list? -- Answer
  • I do not find EPIC (or RGS or OM) processed data in my PPS distribution. Did something go wrong with the pipeline processing? -- Answer

Previous SAS Version related issues

SAS 14.0.0

  • Why do certain tasks end with a fatal error: Unsupported AlgoId? -- Answer
  • Why does phasecalc not give me the correct phase reference epoch? -- Answer
  • The sourcing of the setsas.csh script to initialise SAS, produces the following error:
    SAS_PREV_LD_LIBRARY_PATH: Undefined variable. How to fix this problem? -- Answer
  • In Mac OS X, the execution of some tasks, e.g. epproc, omsource, etc, produces the error:
    dyld: Library not loaded: /sasbuild/local/xmac01/libpng_1.2.51/lib/libpng12.0.dylib
    Referenced from: /Users/user/SAS/xmmsas_20141104_1833/lib/libssc.4.28.dylib
    Reason: image not found
    Trace/BPT trap
    How to fix this problem? -- Answer
  • When the task emosaic_prep is run, it gives the following error:
    Cannot exec "preqgti": No such file or directory at.... How to fix this problem? -- Answer
  • Why epproc/epchain ends with a fatal error: Unsupported ALGOID? -- Answer

SAS 13.5.0

  • Are the recent CCFs compatible with SAS v13.5 ? -- Answer
  • What to do if emosaic_prep doesn't split the mosaic data properly? -- Answer
  • How can OM Fast mode data be processed measuring the background from associated Image mode data? -- Answer
  • Why are there library conflicts when running Heasoft tools? -- Answer
  • Why are ESAS routines within SAS needing special calibration files? -- Answer

SAS 13.0.3

  • Why did the names of the RGS extraction regions change with SAS 13.0? Answer
  • Missing libpng12.0.dylib when running SAS tasks on MacOSX 10.8.5 (Mountain Lion), 10.7.4 (Lion) and 10.6.8 ("Snow Leopard") 64-bit? -- Answer

Issues related to older SAS versions can be found on the SAS watchout archive page.