This page contains warnings concerning the quality of data products in the Chandra Archive, grouped by instrument. For a more detailed description of the data products, visit the Data Products Guide.
All data received from the Chandra X-ray Observatory is processed through the standard data processing (SDP) pipelines at the Chandra X-ray Center. CIAO is designed for use with data with a processing version of "R4CU5UPD8" or "DS6.0.0" or higher; see the Note on Processing Versions for more information. To obtain the most up-to-date processing for a given observation, use download_chandra_obsid or visit the Chandra Data Archive.
If you have any specific questions about your data, please email the Helpdesk.
- The current Calibration Group Homepage
- ACIS Pipeline-Processed Event Data
- ACIS Pipeline-Processed Mask Files
- Spectral analyses of ACIS data with a limited pulse-height range
- ACIS Onboard Event Filtering
- Degredation of Low Energy QE
- Clarification of time-related keywords in FITS header
- Time Keywords in Interleaved Data
- Warm focal plane temperatures
- Extracting Spectra From Merged Datasets
- ACIS Continuous Clocking mode data (imaging) and Calibration Properties of CHANDRA HETG Spectra Observed in CC-Mode (gratings)
- (04 Feb 2021) ACIS badpixels in the shadow cast by the frame store cover -- error in creating ARFs and Exposure maps in CIAO 4.12 and 4.13.
- (10 Mar 2021) Investigating the limits of subpixel resolution given the rate at which Chandra dithers.
Issues affecting specific datasets