Checking your LETG/ACIS-S Obscat setup (updated Feb 2007)

• Spectrum Visualization Tool

LETGS Description

• Complete Proposers' Observatory Guide (html, ps, pdf)
  • Chapter 9: LETG (html)
  • Chapter 7: HRC detector (html)
  • Chapter 6: ACIS detector (html)

Calibration and Performance Issues

Officially released data products are found in the CALDB. Lower-level calibration products used to derive the CALDB files and links to detailed documentation and more recent files generated by the LETGS calibration team are listed below.

Note that these files are in general independent of both CALDB and CIAO and represent the best current understanding of the instrument. In some cases we provide some files which are secondary calibration products that are of direct relevance to data analysis, such as on-axis effective area curves (which fully take into account all effects such as QE non-uniformity, extraction efficiencies, etc.) and grating response matrices (to facilitate the inclusion of higher order dispersion in HRC-S/LETG spectral fitting, which would otherwise not be possible with the current version of CIAO).

• Calibration Status
• Calibration Review/Workshop Presentations, 2001-2007
• Bowtie Spectral Extraction Region
• Higher-Order Diffraction Efficiencies
• HRC-S
  • LETG/HRC-S Effective Area
  • QE
  • LETG/HRC-S Background Filtering and Position-Dependent Gain
          A new gain map and background filter are now available (Nov 2008)
  • Time-Dependent Gain
          This work was updated during development of the new gain map and background filter in 2008. See Section 4 (pages 12-27) of this report (pdf, 2 MB).
  • Degap Map
  • Dispersion Relation
    • Corrections to the Dispersion Relation
• ACIS-S
  • Effective Area and QE
  • Dispersion Relation
  • LETG+ACIS-S C K-edge analysis

Analysis / Software

• CIAO Data Analysis Software
• PINTofALE (contributed spectral analysis software)

Documentation (Papers, Memos)

• Monte Carlo Processes for Including Chandra Instrument Response Uncertainties in Parameter Estimation Studies (PS file)
• Memo on a study of the effects of Compton Scattering on the white dwarf models used for LETG+HRC-S low energy calibration  
  • PS file  
  • Paper submitted to A&A February 2006 (html)  
    • PS file  
• Chandra HRC-S Degapping Corrections (SPIE, Glasgow 2004)  
• Update on the Non-Linearities in the Chandra LETG/HRC-S Dispersion Relation (SPIE, Glasgow 2004)  
  • Characterizing Non-Linearities in the Chandra LETG/HRC-S Dispersion Relation (SPIE, San Diego 2003)  
• Chandra LETG Higher Order Diffraction Efficiencies (SPIE, San Diego 2003)  
• Monitoring the HRC-S Gain with the LETG/HRC-S (CXC Memo 2003)  
• In-flight Effective Area Calibration of the Chandra LETGS (SPIE, Waikoloa 2002)  
  • Low Energy Effective Area of the Chandra LETGS (SPIE, Munich 2000)  
  • (Poster) Mid-Energy Effective Area Calibration of the Chandra LETGS (HEAD, Honolulu 2000)  

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Contact Jeremy Drake (jdrake@cfa.harvard.edu) for further information.

Last modified: 12/08/08

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