README File for CALDB 4.9.1 Full Download Instructions 31 March 2020 DE Graessle, Chandra CALDB Manager Includes brief Intro, Download instructions, Unpacking instructions, 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 This README refers to the FULL CalDB 4.9.1 installation, which should only be necessary here forward with a new installation of CIAO 4.12. CalDB 4.9.1 is a patch upgrade to CalDB 4.9.0. For those who have already downloaded and installed CIAO 4.12 with CalDB 4.9.0, only the patch upgrade file is actually necessary to upgrade your CalDB. CalDB 4.9.1 is compatible with CIAO 4.12 and later versions ONLY! Please do not attempt to upgrade your CalDB for CIAO 4.11 or older versions with CalDB version 4.9.1. None of the ACIS upgrades in CalDB 4.9.1 will be applied with the older software because of required software changes to do so. Furthermore, the HRC-S chip edge offset values will not be applied in CIAO 4.11 with CalDB 4.9.1, and users will not be notified by the software if this occurs. 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 MANUALLY Downloading and Unpacking CALDB 4.9.1 NOTE: The installation of CalDB 4.9.1 may be done automatically by using the new ciao-install routine, as a matter of course, when installing or upgrading CIAO. See the instruction at "Downloading CIAO ", http://cxc.harvard.edu/ciao/download/ Instructions for Downloading (Manually): Download all files into the same directory, where you intend to install your Chandra CALDB 4.9.1. You will need at least 20 GBytes free to download and unpack the basic structure. The ACIS & HRC background files are now packaged separately, so you don't have to install it to get the basic package. The background files add another 6.1 GB to the space you need. See the following ftp links to acquire the CALDB download tar files for version 4.9.1. MAIN CALDB DIRECTORY AND FILES: 1. ftp://cda.harvard.edu/pub/arcftp/caldb/caldb_4.9.1_main.tar.gz The ACIS and HRC-I background files (blank-field files) are now packaged separately, so if you want to use them you will need files 2 and 3. You need these files if you are going to run reproject_events to generate background files for your ACIS or HRC-I observations. 2. The ACIS BKGRND files tar ball was most recently upgraded with CalDB 4.7.6, 18 Aug 2017 to include version N0002 of the Group G event lists (effective 2012-01-01 through the present.) ftp://cda.harvard.edu/pub/arcftp/caldb/acis_bkgrnd_4.7.6.tar.gz 3. The HRC-I BKGRND files tar ball has been newly upgraded in CalDB 4.7.7 (14 Dec 2017), to include the new background files effective for 2015-2017 calendar years, respectively. ftp://cda.harvard.edu/pub/arcftp/caldb/hrc_bkgrnd_4.7.7.tar.gz TABLE 1: Files and sizes: FILE FILENAME Ship Size(byte) Unpacking space md5sum 1 caldb_4.9.1_main.tar.gz 3,551,959,727 8.1 GB 2b71c0e12cae8f8474e199ff46f720b8 2 acis_bkgrnd_4.7.6.tar.gz 1,387,251,364 2.9 GB 192d4871813c9d5d3e857726195d1261 3 hrc_bkgrnd_4.7.7.tar.gz 2,323,747,030 3.2 GB 3c9b4e5d6966929793d726b12ae4a4b2 Instructions for unpacking: 1. Locate a place for your CALDB. Designate an empty directory to be assigned to the value of $CALDB. Unpack file 1 above from that location. 2. It is not necessary to edit the ./software/tools/caldbinit.* files. When you install or load CIAO, the location of the CalDB gets set up to the appropriate directory. 3. Unpack the ACIS "background" files (File 2 in the table above) if you expect to use them. The files take up a large amount of space. 4. Unpack the HRC "background" files (File 3 in the table above) if you expect to use them. The files take up a large amount of space. 5. Delete the tar files. The latest versions will be maintained online at CXC at all times. -- Chandra CALDB Manager