Chandra Proposal Planning

The following links address known issues relating to the usage and accuracy of calibration data files included in the Chandra CalDB. These have been added on an ad-hoc basis, and are by no means exhaustive. More may be added at any time.

38 ACIS archival OBS_IDs with "problem reading tgainfile" from the CalDB: A problem for certain ACIS OBS_IDs whose duration crosses an ACIS T_GAIN epoch boundary. A simple fix to the problem is prescribed.
ACIS Responses Suite version N0005: A discussion of the accuracy of the latest FI chip RMFs with mkacisrmf.
Using the HRC-I RMF: Issues regarding the use of the HRC-I RMF version N0002 in Sherpa/XSPEC.
ACIS T_GAIN FILE ERRORS: ACIS Epoch 42 (May-July 2010) T_GAIN file errors, in CalDB 4.4.1 and 4.4.2.

Introduction: Header Keywords; Directory Structure; Indexing System; Versioning
Download the CALDB4: Download Version 4.5.5.1; Release Notes
Caveats for the Chandra CALDB4: 38 ACIS OBS_IDs with T_GAIN correction problem (posted 24 April 2012); ACIS N0005 Responses Suite Caveat; HRC-I RMF v2 Caveat; ACIS Epoch 42 T_GAIN Error
Querying the CALDB4
Calibration Data
Proposal Planning
References
Release Notes
CXC Links: CIAO (Data Analysis)
Site Map

Analysis Notes

Matching CIAO and CALDB Versions

CALDB 4.5.5.1 should not be used unless you are running CIAO 4.3 or later versions.

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

News

Previous Items

08 Jan 2013 [New]

CalDB 4.5.5.1, a patch upgrade to CalDB 4.5.5, has been released. This minor patch upgrade corrects header keyword omissions in the new ACIS time-dependent QEU files originally released in CalDB 4.5.5 below. See the CalDB 4.5.5.1 Release Notes for details.

13 Dec 2012 [New]

CalDB 4.5.5, a cumulative upgrade to CalDB 4.4.7 through 4.5.4, includes the following: ACIS T_GAIN Epoch 51, ACIS time-dependent QEUs, HRC-I 2012 GMAP and PIBGSPEC updates, HRC-S QE for post-HV-adjust OBS_IDs, the PIMMS CY15 Effective areas, and (once again!) RE-re-corrected ACIS Group E blank-sky background files. See the CalDB 4.5.5 Release Notes for details.

15 Oct 2012

CalDB 4.5.3, a cumulative upgrade to CalDB 4.4.7 through 4.5.2, includes the RE-corrected ACIS Group E blank-sky background files, as promised on 04 Oct 2012, when an error was discovered. See the CalDB 4.5.3 Release Notes for details.

27 Sep 2012

CalDB 4.5.2, a cumulative upgrade to CalDB 4.4.7 through 4.5.1, includes the latest ACIS T_GAIN Epoch 50 quarterly updates. NOTICE as of 04 Oct 2012: The included ACIS Group E BKGRND files version N0002 that were supposed to be corrected are still problematic. They will be replaced ASAP. See the CALDB 4.5.2 Release Notes for details.

24 Jul 2012

CalDB 4.5.1, an upgrade to CalDB 4.4.7 through 4.5.0. This upgrade includes upgrades to the HRC-S time-dependent gain (T_GMAP) file originally released in December 2009. It adds corrections for 2012 Obs_IDs with HRC-S/LETG at either the old or new HRC-S HV settings, which were changed on 29 March 2012. See the CalDB 4.5.1 Release Notes for details.

27 Jun 2012

CalDB 4.5.0, an upgrade to CalDB 4.4.7 through 4.4.10. This upgrade includes fixes to the CalDB for certain OBS_IDs that have trouble in reprocessing or analysis due to incorrect calibration validity end dates. It also include new HRC-I and HRC-S GAPLOOKUP (DEGAP solution) files relevant for imaging, LETGS, and timing data. See the CalDB 4.5.0 Release Notes for details.

30 May 2012

CalDB 4.4.10, a patch upgrade to CalDB 4.4.7 and 4.4.8. This upgrade includes latest ACIS Contamination Correction (CONTAM) upgrade version N0007, and the latest T_GAIN corrections from Epoch 49 (Feb-Apr 2012). See the CalDB 4.4.10 Release Notes for details.

24 Apr 2012

A new CAVEAT PAGE has been added with instructions to correct a problem reading the T_GAIN file from CalDB for 38 specific ACIS archival OBS_IDs.

23 Feb 2012

CalDB 4.4.8, a patch upgrade to CalDB 4.4.x. This upgrade includes latest ACIS T_GAIN corrections from Epoch 48 (Nov 2011-Jan 2012). See the CalDB 4.4.8 Release Notes for details.

15 Dec 2011

CALDB 4.4.7, a patch upgrade to CalDB 4.4.x, which includes only the latest ACIS T_GAIN Epoch 47 updates, HRC-I GMAPS and PIBGSPEC files for 2010, 2011, and HRC-S QE version N0011. See the CalDB 4.4.7 Release Notes for more information.

15 Dec 2011

CY15 Proposal Planning files have been released, with the new CfP.