Data Caveats

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, visit the Chandra Data Archive.

If you have any specific questions about your data, please email the Helpdesk.

General

The current Calibration Status Report

• Chandra Aimpoint Shift
• Files with Multiple GTI Subspace Components (28 Feb 2013)

ACIS

• 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
• Zero-exposure Event File
• Incorrect Data Products for Jupiter (ObsIDs 2398,2399,2400,2401,2407,2408)
• Warm focal plane temperatures
• Extracting Spectra From Merged Datasets (7 Dec 2012)

HRC

• Instrument Anomalies in the HRC
• HRC-S Event Position Errors Near the Aim Point
• HRC Deadtime Correction with Telemetry Saturation
• LETG+HRC-S Dispersion Relation
• HRC-S Focus Position Change on 6 November 1999
• Out of Sequence Events
• Timing Anomalies
• Time Gaps in HRC Data
• Merging HRC datasets from different processing versions. (12 Feb 2013)

Aspect

• Aspect Caveats
• Chandra Astrometric Accuracy

PSFs

• Probing higher resolution: an asymmetry in the Chandra PSF