README File for CALDB 4.8.5 Upgrade Only Instructions 05 November 2019 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 4.8.5, see http://cxc.harvard.edu/caldb/downloads/releasenotes.html These instructions apply only to those wanting to upgrade their CalDB version 4.8.2 or later version to version 4.8.5 quickly, installing only the updated calibration files and index updates. You must have installed CalDB 4.8.2 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 4.8.5 ------------------------------------------------------------------------------------------ I. Introduction CalDB 4.8.5 is an upgrade to the Chandra CalDB, which includes the following items: * ACIS CONTAM version N0013 For the CIAO 4.11 / CalDB 4.8.5 release notes see How CalDB 4.8.5 Affects Your Analysis, at http://cxc.harvard.edu/ciao/releasenotes/ciao_4.11_release.html#HowCALDB4.8.5AffectsYourAnalysis ------------------------------------------------------------------------------------------ II. SUMMARY OF CHANGES Location: $CALDB/data/chandra/acis/contam/ Filename: acisD1999-08-13contamN0013.fits Analysis of recent observations of previously-observed cosmic sources, such as certain clusters of galaxies and supernova remnants, have resulted in unexpected increased temperatures and reduced flux levels that have been traced to a deviation of the ACIS contaminant model (CONTAM in CalDB) from calibration measurements. Hence it is time to update this model, specifically to improve its performance since about 2018 for center-array optical depths and for center-to-edge spatial modeling since about 2015. More specifically, the new model specifies a linear layer depth with time since 2016, as well as a linear center-to-edge dependence with time since around 2010-2011. The current and new models are compared with calibration data in the technical details section below. See the why page for more general information on the ACIS OBF contaminant. CIAO SCRIPTS/TOOLS AFFECTED: See the script fluximage, which uses mkinstmap See the script specextract, which uses mkwarf See the script fullgarf, which uses mkgarf THREADS AFFECTED: For exposure-corrected imaging analysis with ACIS, see the threads: Single Chip ACIS Exposure Map and Exposure-corrected Image Multiple Chip ACIS Exposure Map and Exposure-corrected Image For imaging spectroscopy with ACIS, see the threads: Extract Spectrum and Response Files for a Pointlike Source Extract Spectrum and Response Files for an Extended Source Extract Spectrum and Response Files for Multiple Sources For grating spectroscopy with ACIS, see the threads: HETG/ACIS-S Grating ARFs LETG/ACIS-S Grating ARFs ------------------------------------------------------------------------------------------ III. Instructions for installing the upgrade from CalDB 4.8.2 or later version to 4.8.5. The following are manual installation instructions. You may also download and install CalDB 4.8.5 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 4.8.2 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 4.8.2 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_4.8.5_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_4.8.5_upgrade.tar.gz 307,116,051 2.1 GB f25837e7268aa726ccdeae054c7612bd 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_4.8.5_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