Why Topics

The "why" topics are a second layer to the threads; they provide supplemental information for the user that is interested in digging deeper. Some of the topics highlight common pitfalls and subtleties in the CIAO software, others describe aspects of the Chandra Observatory and data obtained with it. The documents also provide information on why certain science decisions are made, enabling the user to tailor the analysis to a particular dataset.

Please email the Helpdesk if you have suggestions for topics that you would like to see discussed here.

Data Products

• The Aspect Solution & pcad_asol1.fits Files
• Dither
• Multi-OBI Observations

ACIS

• ACIS CTI Correction
• ACIS Time-dependent Gain
• ACIS QE Degradation
• ACIS Dead Area Correction
• Choosing an Energy Filter
• Continuous Clocking Mode
• Creating ACIS RMFs with mkacisrmf
• Destreaking ACIS Data

Pileup

• An Overview of Pileup
• When and How to Avoid Pileup (or not!)

CALDB Upgrades

• CALDB 3.2.1
  • HRMA Effective Area
  • HRC-I RMF
  
  
• CALDB 3.0.1
  • PIXLIB Geometry File
  • HRC-S QE and QEU
  
  
• CALDB 2.28
  • QEU Comparison

Miscellaneous

• S-Lang as the CIAO Scripting Language
• Timing Analysis with Lightcurves