README File for CALDB 4.7.7 Upgrade Only Instructions 12 Dec 2017 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 4.7.7, see http://cxc.harvard.edu/caldb/downloads/releasenotes.html CalDB 4.7.7 requires CIAO 4.5 (or later version) because of an upgrade to the caldb4 software that was included since the release of CIAO 4.5 in December of 2012. The caldb4 upgrade in question provides for the proper selection of time-displaced CalDB files with overlapping validity date ranges, which does not exist in earlier CIAO versions. CalDB 4.7.7 is optimized for CIAO 4.8 (or later version) which includes an upgrade to the acis_process_events tool for handling CC-mode observations, specifically to perform the CTI-correction properly for them. As a result, the EDSER SUBPIX algorithm is now applied in a-p-e to CC-modes, where it had not been before. These instructions apply only to those wanting to upgrade their CalDB version 4.7.3 or later version to version 4.7.7 quickly, installing only the updated calibration files and index updates. You must have installed CalDB 4.7.3 or later version previously, or this upgrade installation will not work correctly. 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 4.7.7 ------------------------------------------------------------------------------------------ I. INTRODUCTION CalDB 4.7.7 is an upgrade to the Chandra CalDB, which includes the following items: HRC-I GMAP for 2017-09-17 HRC-I PIBGSPEC for 2017-09-17 HRC-I BKGRND Event Lists for 2015-2017 PIMMS CYCLE 20 Effective Areas For the CIAO 4.9 / CalDB 4.7.7 release notes see How CalDB 4.7.7 Affects Your Analysis. ------------------------------------------------------------------------------------------ II. SUMMARY OF CHANGES A. HRC-I GMAP for 2017-09-17 Location: $CALDB/data/chandra/hrc/gmap/ Filename: hrciD2017-09-17sampgainN0001.fits The September 2017 adjustment to the HRC-I time-dependent gain map has been calibrated and has been released. The rate of gain decay continues to increase with time; however the HRC calibration team has determined that an annual GMAP adjustment is adequate to maintain approximately 2-4% global accuracy in the gain. The same set of ArLac observations has been used to measure the gain corrections. Details including a plot of the new GMAP and its differences with the previous corrections for 2015 are included in the technical details section of the online CalDB 4.7.7 release notes. As with previous HRC-I GMAP updates, these changes will apply only to recent HRC-I observations, specifically those with DATE-OBS later than 2017-09-17T12:00:00 UTC. See the HRC-I gain map why page for more information. PIPELINES/TOOLS AFFECTED: DS and CIAO level 1 (re)processing tool hrc_process_events Also: CIAO reprocessing script chandra_repro THREADS AFFECTED: Reprocessing Data to Create a New L2 Events File B. HRC-I PIBGSPEC for 2017-09-17 Location: $CALDB/data/chandra/hrc/pibgspec/ Filename: hrciD2017-09-17pibgspecN0001.fits Along with the new 2017 HRC-I GMAP, the incumbent PIBGSPEC for September 2017 is also being released. The PI background spectrum changes with the GMAP, because background events reprocessed using the new GMAP, using the point-source observations as are used to generate the new GMAP. This results in a shift in the background spectrum in channel space relative to the previous spectrum file. Details of how the derivation is done, and a plot of the new spectrum in comparison with previous PIBGSPEC files are given in the technical details section in the CalDB 4.7.7 online release notes. PIPELINES/TOOLS AFFECTED: CIAO tool hrc_bkgrnd_lookup. THREADS AFFECTED: HRC-I Background Spectra Files C. HRC-I BKGRND Event Lists for 2015-2017 Location: $CALDB/data/chandra/hrc/bkgrnd/ Filenames: hrciD2015-01-01bkgrndN0003.fits hrciD2016-01-01bkgrndN0001.fits hrciD2017-01-01bkgrndN0001.fits As per the original HRC Stowed Position Background Study, the CalDB is to be annually updated with HRC-I background event lists effective for one full calendar year. As indicated in the contributed page How to Create a Background Map for an Observation, one updated and two more new HRC-I stowed-position background data sets have been compiled and released to users applicable to calendar years 2015 through 2017, respectively. These have been adapted to CalDB and the applicable CIAO thread for generating fluxed images using the BKGRND files. The "time" columns were removed, the EXPOSURE keywords with appropriate values have been added to the headers, along with the CalDB indexing keywords. These are to be added to the existing 15 annually displaced HRC-I BKGRND files already present in CalDB, which extended from 2000 to 2015 previously. See the HRC-I Background Vignetting why page for more information on use of the HRC-I BKGRND event lists to remove vignetting rings from exposure maps. PIPELINES/TOOLS AFFECTED: CIAO tool reproject_events is used to tailor an appropriate HRC-I BKGRND event list to a give observation. The CIAO script fluximage selects the appropriate BKGRND file from CalDB, and uses it to generate background-subtracted fluxed images. THREADS AFFECTED: The HRC-I Background Event Files HRC-I Exposure Map and Exposure-corrected Image III. Instructions for installing the upgrade from CalDB 4.7.3 or later version to 4.7.7. ---------------------------------------------------------------------------------- The following are manual installation instructions. You may also download and install CalDB 4.7.7 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 4.7.3 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 4.7.3 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_4.7.7_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 4.7.0 (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_4.7.7_upgrade.tar.gz 445,163,618 2.8 GB 0343f93ecbf62330517731a71d2379b1 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_4.7.7_upgrade.tar.gz gtar xvfz acis_bkgrnd_4.7.6.tar.gz gtar xvfz hrc_bkgrnd_4.7.0.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