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Welcome to the
Chandra Calibration Database Website

The Chandra X-Ray Center has introduced version 4.11.6 of the Chandra Calibration Database (CALDB) on 17 December 2024.

CalDB 4.11.6 has been released, for use in CIAO 4.17, and users are encouraged to download both using the Conda or ciao-install procedures.

See the CIAO web page for links to instructions using either Conda, or the new upgraded ciao-install, for an automated installation of CIAO 4.17 and CalDB 4.11.6 on your local system. Or for manual instructions, see the CalDB Downloads page to install or upgrade your Chandra CalDB to CalDB 4.11.6.

CalDB 4.11.6 includes the following updates:

See details in the links CalDB 4.11.6 Release Notes.

The CALDB is the directory and indexing structure that stores and provides access to all calibration files that are required for standard processing and analysis.

These files are used in standard data processing, as well as for analysis with software packages such as CIAO. When you apply a gain map, create an exposure map, or build response files (RMFs and ARFs) - among many other things - you are using the Chandra CALDB to apply the necessary calibration files.

The CALDB serves many functions:

Storing and archiving calibration files.
Maintaining a naming convention and header structure for all calibration files.
Indexing calibration data, based on FITS header keywords, for software access.
Permitting updates of calibration data independent of software updates, while maintaining configuration control.
Providing a traceable history of calibration data in the database by maintaining versioning.
Translating calibration products into formats suitable for processing and/or analysis.

These webpages contain information about each of these topics. They are also designed to help you (or your system manager) understand how the CALDB is assembled and how it works in the Chandra software system.

Please email the CXC Helpdesk with any questions or comments on the CALDB and this website.

Analysis Notes

Matching CIAO and CALDB Versions

CALDB 4.11.6 should not be used unless you are running CIAO 4.16 or later versions!

Are your versions mismatched? Time to upgrade CIAO and CALDB!

News

17 Dec 2024 [New]

CalDB 4.11.6 has been released to the public. Included in this release are (1) the HRC-I QE N0016 file set, (2) PCAD ACA-P DARK_CURR file updates #9, and (3) Proposal Cycle 27 PIMMS Effective Areas. See the CalDB 4.11.6 Release Notes

21 Aug 2024

CalDB 4.11.5 has been released to the public. Included in this release are HRC-S QE version N0017, and QEU version N0020 file sets as well as two new ACA-P DARK_CURR files (periodic updates #8), which do not affect CIAO. See the CalDB 4.11.5 Release Notes for details.

21 Aug 2024

CalDB 4.11.3 has been released to the public. Included in this release is an updated HRC-S QEU time-dependent file set version 19 (34 new files), as well as four new ACA-P DARK_CURR files (periodic updates #7), which do not affect CIAO. See the CalDB 4.11.3 Release Notes for details.

06 Jun 2024

CalDB 4.11.2 has been released to the public. Included in this release is an updated HRC-I QE time-dependent file set version 15 (38 new files). See the CalDB 4.11.2 Release Notes for details.

18 Apr 2024

CalDB 4.11.1 has been released to the public. Included in this release are the new ACIS "warm-temperature" CTI corrections vN0012, and an updated HRC-S QEU N0018 file set (33 new files). Also included are set #6 of the PCAD ACA-primary DARK_CURR (dark current) image files. See the CalDB 4.11.1 Release Notes for details.

12 Dec 2023

CalDB 4.11.0 has been released to the public. Included in this release are the new ACIS "warm-temperature" CTI corrections vN0011, and an updated HRC-I QE N0014 file set (37 new files). Also included are set #5 of the PCAD ACA-primary DARK_CURR (dark current) image files and the Cycle 26 PIMMS Effective Area configuration files, neither of which affect CIAO users. See the CalDB 4.11.0 Release Notes for details.

14 Dec 2023

CfP Cycle 26 Release Cycle 26 PIMMS Effective areas information, ACIS and GRATING sample (G)RMFs and (G)ARFs for proposal planning by non-CIAO users.

14 Sep 2023

CalDB 4.10.7 has been released to the public. Included in this release are the latest HRC-S QE Uniformity data sets (version N0017) including one addtional data set effective for OBS_IDs taken after the HRC-S restart. Also included are more PCAD ACA-primary DARK_CURR (dark current) image files, which do not affect CIAO users. See the CalDB 4.10.7 Release Notes for details.

22 Mar 2023

CalDB 4.10.4 has been released to the public. Included in this release are the latest ACIS T_GAIN (time-dependent gain) updates, which will be updated annually rather than semiannually going forward. Also included with this release are PCAD ACA-primary DARK_CURR (dark current) image files, which do not affect CIAO users. See the CalDB 4.10.4 Release Notes for details.

15 Dec 2022

15 Nov 2022

CalDB 4.10.2 has been released to the public. Included in this release is the latest ACIS OBF Contamination (CONTAM) model (v N0015) upgrade, which adjusts for recent (2020-2022) increases in the contamination rate relative to the older model (v N0014). See the CalDB 4.10.2 Release Notes for details.

16 Jun 2022

CalDB 4.9.8 has been released to the public. Included in this release are PCAD ALIGN file updates (18 new files, six-month intervals, extending from 2013-2021); HRC-I/Grating angle corrections in the PIXLIB GEOM file vN0007; HRC-S QE Uniformity upgrade version N0016 with and additional new file for new observations. See the CalDB 4.9.8 Release Notes for details.

24 Mar 2022

CalDB 4.9.7 has been released to the public. Included in this release are ACIS T_GAIN upgrades for Epochs 85+86 (effective 2021-05-02, finalized) and epochs 87+88 (effecive 2021-11-01, provisional), and expanded FP_TEMP boundary conditions for certain ACIS CalDB files applicable to current and future datasets, to accommodate warmer ACIS calibration observations to be taken in the near future. See the CalDB 4.9.7 Release Notes for details.

24 Sep 2021

CalDB 4.9.6 has been released to the public. Included in this release are ACIS T_GAIN upgrades for Epochs 83+84 (effective 2020-11-01, finalized) and epochs 85+86 (effecive 2021-05-02, provisional), HRC-S T_GMAPs v4, QE v16, and QEU v15, as well as HRC-I QE v13. See the CalDB 4.9.6 Release Notes for details.

29 Apr 2021

CalDB 4.9.5 has been released to the public. Included in this release are ACIS T_GAIN upgrades for Epochs 81+82 (effective 2020-05-02, finalized) and epochs 83+84 (effecive 2020-11-01, provisional), as well as a new ACIS-S3 CTI correction file for observations taken since 2020-01-01. HRC-I/LETG +/- 1st order LSF parameter files have also been added. See the CalDB 4.9.5 Release Notes for details.

16 Dec 2020

CalDB 4.9.4 has been released to the public. Included in this release are the ACIS CONTAM N0014 upgrade, an HRC-S QEU N0014 upgrade with 29 new files for the library, and a delayed upgrade to the HRC-S PI Region background filter file N0002. See the CalDB 4.9.4 Release Notes for details.