CalDB 4.12.4 Public Release Notes
Public Release Date: 23 APR 2026
(Public Release Only)
I. INTRODUCTION
CalDB 4.12.4 is an upgrade to the Chandra CalDB, which includes the following items:
For the CIAO 4.18 / CalDB 4.12.4 release notes see How CalDB 4.12.4 Affects Your Analysis.
II. SUMMARY OF CHANGES
A. Removal of old ACIS CONTAM Files
| Location: | $CALDB/data/chandra/acis/contam/ |
| Filenames: | acisD1999-08-13contamN0004.fits acisD1999-08-13contamN0005.fits acisD1999-08-13contamN0006.fits acisD1999-08-13contamN0007.fits acisD1999-08-13contamN0008.fits acisD1999-08-13contamN0009.fits acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0011.fits acisD1999-08-13contamN0012.fits acisD1999-08-13contamN0013.fits acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
The above files have been upstaged by the current CONTAM file (N0016) in CALDB, and are now being retired (removed) from the distribution and the ACIS Branch Index file. They are instead being made available in a separate download tar file from the CalDB ARCFTP download site. The files may be "pset" manually into a user's ardlib.par configuration should they want to use them to repeat old analysis results, for example.
This action is being taken to reduce the size of the CalDB download tar files.
See the ACIS QE Contamination why page for more information.
PIPELINES/TOOLS AFFECTED:
None.
THREADS AFFECTED:
None.
B. ACIS P2_RESP (mkacisrmf) Lower Limit Reduction
| Location: | $CALDB/data/chandra/acis/p2_resp |
| Filename: | acisD2000-01-29p2_respN0009_119-120.fits |
The ACIS P2_RESP file set version N0009 currently has a lower FP_TEMP limit of 152.96K (-120.19C), specifically in the low-temp file listed above. In the recent CSC 2.2 (Level 3) processing, and OBS_ID (26030) was run, generating a CalDB file search error in mkacisrmf, due to the FP_TEMP for that OBS_ID being below the above lower limit value. Naturally, users analyzing that same or similarly disposed OBS_IDs would have the same problem generating ACIS RMFs with the current P2_RESP file configuration.
To remedy this situation, the CXC CalDB Manger is lowering the FP_TEMP boundary condition limit to -125.00C (148.15K). The ACIS Calibration Team concurs with this change to accommodate very cold OBS_IDs.
See the Creating ACIS RMFs why page for more information.
PIPELINES/TOOLS AFFECTED:
None.
THREADS AFFECTED:
None.