README File for CALDB 4.9.1 Upgrade Only Instructions 31 March 2020 DE Graessle, Chandra CALDB Manager Includes brief Intro, Upgrade download and installation instructions, and pointers for further assistance. To learn more about the Chandra CALDB, and to find this information on the WEB, you are referred to http://cxc.harvard.edu/caldb/index.html. For Release Notes to the Chandra CALDB4, and specifically CalDB 4.9.1, see http://cxc.harvard.edu/caldb/downloads/releasenotes.html These instructions apply only to those wanting to upgrade their CalDB version 4.9.0 or later version to version 4.9.1 quickly, installing only the updated calibration files and index updates. You must have installed CalDB 4.9.0 or later version previously, or this upgrade installation will not work correctly. CalDB 4.9.1 is compatible with CIAO 4.12 or later versions only. It is NOT to be used with CIAO 4.11 or any ealier versions of CIAO. Be sure to use the CIAO command "check_ciao_caldb" to verify your CalDB version before proceeding with these instructions. Condensed Release Notes for CalDB 4.9.1 ------------------------------------------------------------------------------------------ I. Introduction CalDB 4.9.1 is an upgrade to the Chandra CalDB, which includes the following items: * ACIS T_GAIN Epochs 79+80 * ACIS DET_GAIN/P2_RESP N0008 * HRC-S QEU Version N0013 file set * ASPECT FDC N0004 Plate Scale Upgrades For the CIAO 4.12 / CalDB 4.9.1 release notes see How CalDB 4.9.1 Affects Your Analysis, at http://cxc.harvard.edu/ciao/releasenotes/ciao_4.12_release.html#HowCALDB4.9.1AffectsYourAnalysis ------------------------------------------------------------------------------------------ II. SUMMARY OF CHANGES A. ACIS T_GAIN Epochs 79+80 Location: $CALDB/data/chandra/acis/t_gain/ Filename: acisD2019-05-02t_gain_biN0002_revA.fits acisD2019-05-02t_gainN0002_revA.fits acisD2019-05-02t_gainN0005.fits acisD2019-05-02t_gainN0006.fits acisD2019-11-01t_gain_biN0002.fits acisD2019-11-01t_gainN0002.fits The ACIS Calibration team has released the semiannual time-dependent gain (T_GAIN) updates from analysis of External Calibration Source (ECS) data for the period Aug 01 2019 through Jan 31 2020 (epochs 79+80), and hence the above files have been generated as a result, for immediate release. The secular time variations in the corrections calculated from these new data are similar in magnitude and direction to previous upgrades, wherein maximal changes are a few percent or less of the deltaE/E value. NOTE: Users with observations taken between (DATE-OBS=) 2019-05-02T12:00:00 and 2019-11-01T00:00:00 are advised to reprocess with their data with finalized versions of the applicable T_GAIN files. Users with observations taken since 2019-11-01T00:00:00 will have access to an updated provisional T_GAIN file (one of the version N0002 filenames above); They will not however have a finalized T_GAIN until after Epochs 81+82 (Feb 01 - Jul 31 2020) are completed. PIPELINES/TOOLS AFFECTED: ACIS Level 1 pipeline tool acis_process_events. CIAO script chandra_repro uses acis_process_events to reprocess ACIS observation data. THREADS AFFECTED: Reprocessing Data to Create a New Level=2 Event File B. ACIS DET_GAIN/P2_RESP N0008 Location: $CALDB/data/chandra/acis/det_gain/ Filename: acisD2000-01-29gain_ctiN0008.fits Location: $CALDB/data/chandra/acis/p2_resp/ Filename: acisD2000-01-29p2_respN0008.fits A small depression in the gains at mid-chip (+/- 20 columns around CHIPX=512) of the ACIS Front-illuminated (FI) chips has persisted since the beginning of the mission, but has not yet been accounted for in the DET_GAIN or T_GAIN files for ACIS for these chips. The FI chips are ACIS-0, 1, 2, 3, 4, 6, 8, and 9. It appears as a 1-3% "droop" in the pulse heights with some energy dependence. The effect has been corrected in the DET_GAIN files version N0008 above, for non-GRADED mode cases only at this point. The corrections have been effected using ACIS External Calibration Source (ECS) data only, specifically the available lines Mn-L complex, Al-Ka, Ti-Ka, and Mn-Ka and -Kb. Corrections have been implemented for all eight of the FI chips over the full chip. The tiling of the FI chips DET_GAIN data has been changed from 256 x 32 pixels (in chipx, chipy) to 32 x 32 pixels. It was original the tiling of the FI chip DET_GAIN data that in fact resulted in ignoring the gain droop as a matter of course in the ACIS FI chip gain calibrations; That is being addressed in DET_GAIN version N0008, which hence contains a considerably larger array of data for each FI chip. Hence the file size is much larger than its predecessors. Regarding the N0008 P2_RESP file, there is no change to the FI chip (or BI chip) RMF calibrations themselves, but only in the FI chip gains as they apply to the RMFs. Structurally, only the third and fourth extensions (Blocks 4 and 5) have changed, and only to accommodate the changes in the DET_GAIN file tiling as described above. That is, the only reason this P2_RESP file had to be updated was to keep it properly adjusted to the FI-chip mid-chip gain droop corrections. However, because the tile numbering has changed, the output of mkacisrmf will appear somewhat different as well, for both FI and BI (back-illuminated) chips. PIPELINES/TOOLS AFFECTED: ACIS Level 1 pipeline tool acis_process_events. CIAO script chandra_repro uses acis_process_events to reprocess ACIS observation data. THREADS AFFECTED: Reprocessing Data to Create a New Level=2 Event File C. HRC-S QEU Version N0013 file set Location: $CALDB/data/chandra/hrc/qeu/ Filenames: hrcsD1999-07-22qeuN0013.fits hrcsD2000-01-01qeuN0013.fits hrcsD2001-01-01qeuN0013.fits hrcsD2002-01-01qeuN0013.fits hrcsD2003-01-01qeuN0013.fits hrcsD2004-01-01qeuN0013.fits hrcsD2005-01-01qeuN0013.fits hrcsD2006-01-01qeuN0013.fits hrcsD2007-01-01qeuN0013.fits hrcsD2008-01-01qeuN0013.fits hrcsD2009-01-01qeuN0013.fits hrcsD2009-08-08qeuN0013.fits hrcsD2010-09-14qeuN0013.fits hrcsD2012-03-29qeuN0013.fits hrcsD2012-10-05qeuN0013.fits hrcsD2013-09-21qeuN0013.fits hrcsD2015-02-17qeuN0013.fits hrcsD2016-02-22qeuN0013.fits hrcsD2016-07-28qeuN0013.fits hrcsD2017-01-23qeuN0013.fits hrcsD2017-06-05qeuN0013.fits hrcsD2017-09-26qeuN0013.fits hrcsD2018-01-19qeuN0013.fits hrcsD2018-05-27qeuN0013.fits hrcsD2018-09-26qeuN0013.fits hrcsD2019-02-24qeuN0013.fits hrcsD2019-08-22qeuN0013.fits As the LETGS calibration team continues to monitor the accelerated rate of decay in the HRC-S quantum efficiency as a function of wavelength, they have elected to replace the current set of time dependent QE Uniformity (QEU) files (version N0012) with another new set of files, now version N0013. One additional file has been added to the set, with new effective date of 2019-08-22T00:00:00, so that the set includes 27 files now. CIAO SCRIPTS/TOOLS AFFECTED: See the script fluximage, which uses mkinstmap THREADS AFFECTED: For exposure-corrected imaging analysis with HRC-S, see the thread: HRC-S Exposure Map and Exposure-corrected Image For grating spectroscopy with the LETG/HRC-S, see the thread: LETG/HRC-S Grating ARFs D. ASPECT FDC N0004 Plate Scale Upgrades Location: $CALDB/data/chandra/pcad/fdc/ Filename: acapD1999-07-22fdcN0004.fits The star and fid light aca plate scale coefficients in the FDC CALDB describe polynomials which convert from CCD (row, col, ACA housing temperature) to (Y_angle, Z_angle). The Chandra ASPECT calibration team has upgraded the FDC CALDB file with a recalibration that significantly reduces error in recent data due to increased ACA house temperature. This new calibration preserves performance in historical data at colder ACA housing temperatures. The new calibration for both stars and fid lights has been verified over a set of observations covering the range of observed ACA housing temperatures and shows expected results. The calibration process and validation are captured in Jupyter notebooks at https://cxc.cfa.harvard.edu/mta/ASPECT/aca_plate_scale/calib_2020/. PIPELINES/TOOLS AFFECTED: The ASPECT Level 1 pipeline in DS 10.8.3, implemented on 24 March 2020. THREADS AFFECTED: NONE. Aspect pipeline tools are not available in CIAO. ------------------------------------------------------------------------------------------ III. Instructions for installing the upgrade from CalDB 4.9.0 or later version to 4.9.1. The following are manual installation instructions. You may also download and install CalDB 4.9.1 using the "ciao-install" script at http://cxc.harvard.edu/ciao/download/, or follow the instruction at http://cxc.cfa.harvard.edu/caldb/downloads/index.html. Before you begin, you must have write privileges in your local CalDB area. If you don't have your system administrator do this upgrade! A. As system admin, verify your current CalDB version. With CIAO installed and loaded, enter the command "check_ciao_caldb" If you do not see that the CalDB version is 4.9.0 or later version, you need to use the MAIN CalDB download procedure from Table 1 of the CIAO CalDB downloads page. If the version shown is 4.9.0 or later, proceed with the following: B. Downloading Instructions: Set your working directory to $CALDB, and verify that you are there. Please download the "upgrade" tar ball and either or both of the other tar balls you may need (as indicated below) into the $CALDB area. The following FTP links will allow you to access the files from the Chandra Data Archive. You may also use your web browser to locate the CalDB Download instructions, and proceed from there: http://cxc.harvard.edu/caldb/downloads/index.html CALDB UPGRADE FILE: ftp://cda.harvard.edu/pub/arcftp/caldb/upgrade/caldb_4.9.1_upgrade.tar.gz The ACIS BKGRND files have been updated to include (1) eleven N0002 files in Group G for 2012-01-01 through the present. Added as of the release of CalDB 4.7.6 on 18 Aug 2017. ftp://cda.harvard.edu/pub/arcftp/caldb/acis_bkgrnd_4.7.6.tar.gz Three new HRC-I BKGRND files, effective for calendar years 2015-2017 respectively, have been added to the CalDB as of version 4.7.7 (14 Dec 2017). As has been the case since their original addition to CalDB, they are packaged separately in the following tar file: ftp://cda.harvard.edu/pub/arcftp/caldb/hrc_bkgrnd_4.7.7.tar.gz TABLE 1: Files, sizes, and md5sum values: FILENAME Ship Size Unpacking space md5sum (bytes) caldb_4.9.1_upgrade.tar.gz 137,250,376 1.5 GB 710395f89480941532815d97ecd7ddcf acis_bkgrnd_4.7.6.tar.gz 1,387,251,364 2.9 GB 192d4871813c9d5d3e857726195d1261 hrc_bkgrnd_4.7.7.tar.gz 2,323,747,030 3.2 GB 3c9b4e5d6966929793d726b12ae4a4b2 C. Unpacking instructions: We prefer that you use gtar with the appropriate options to unzip and untar the files in a single step, to save disk space and to apply the safest unpacking procedures: gtar xvUfz caldb_4.9.1_upgrade.tar.gz gtar xvfz acis_bkgrnd_4.7.6.tar.gz gtar xvfz hrc_bkgrnd_4.7.7.tar.gz LINUX users: You may omit the "U" uption in the first gtar command. D. Upgrade verification checks See the CalDB downloads web page for steps to verify your upgrade installation, at http://cxc.harvard.edu/caldb/downloads/index.html#dl_config. - Dale Graessle Chandra CalDB Manager