CALDB Public Release Notes Version: 2.12 Date: 14 FEB 2002 10:30 EST CALDB Effective Date: 2002-02-14T17:00:00 I. Summary of Changes A. HRC-S quantum efficiency (QE V5) and QE Uniformity (QEU V3) FILENAMES: hrcsD1999-07-22qeN0005.fits hrcsD1999-07-22qeuN0003.fits LOCATION: $CALDB/data/chandra/hrc/bcf/qe/ These new HRC-S QE/QEU files make it possible to use mkgarf to produce grating ARFs for LETG/HRC-S. These may be used in Sherpa in conjunction with specific EEARF files (Section B below) to analyze data and produce publishable results. B. LETG/HRC-S EEARF files for use in Sherpa FILENAMES: hrcsleg-1D1999-07-22eearfN0001.fits hrcsleg1D1999-07-22eearfN0001.fits LOCATION: $CALDB/data/chandra/tel/grating/letg/cpf/arf/ We are including the above files in the CALDB for the convenience of users and for clarity in the threads. They are essentially identical to the files provided on the LETG Effective Area web page for use with GARFs produced by mkgarf in CIAO. The LETG EA web page is http://cxc.harvard.edu/cal/Links/Letg/U ser/Hrc_QE/ea_index.html. Their EEARF files are as follows: http://asc.harvard.edu/cal/Links/Letg/User/Hrc_QE/EA/extract_effic/hrcsleg1_eea rf_p_001.fits (+ 1st order) http://asc.harvard.edu/cal/Links/Letg/User/Hrc_QE/EA/extract_effic/hrcsleg1_eea rf_n_001.fits (- 1st order) They must be used when mkgarf grating ARFs are employed for this configuration, until further notice. C. ACIS GRADE "CORNERS" keyword correction (Grade V2) FILENAME: acisD1996-11-01gradeN0002.fits LOCATION: $CALDB/data/chandra/acis/bcf/grade/ The only change here was to correct the CORNERS keyword from "1" to "2" (INT4). This was to make the file consistent with the one used in standard data processing (SDP). In the near future, SDP will begin using the same grade file as CIAO, directly from the CALDB, and we want the files to be the same before making the software switch. This change does not affect most CIAO users at all. (See section II.C below). D. ACIS Background Blank-field files (Effective 2000-12-01 - 2001-12-01) FILNAMES: acis23sD2000-12-01bkgrndN0001.fits acis5sD2000-12-01bkgrndN0001.fits acis6iD2000-12-01bkgrndN0001.fits acis6sD2000-12-01bkgrndN0001.fits acis7iD2000-12-01bkgrndN0001.fits acis7sD2000-12-01bkgrndN0001.fits acis8iD2000-12-01bkgrndN0001.fits acis8sD2000-12-01bkgrndN0001.fits acisiD2000-12-01bkgrndN0001.fits LOCATION: $CALDB/data/chandra/acis/bcf/bkgrnd/ Maxim Markevitch has produced another in a continuing series of ACIS background files from blank-field data that have been compiled during the year 2001. The ACIS background is quite variable depending on particle fluxes in the Chandra environment; hence time-dependent files are needed here. His ACIS background memorandum is available at http://cxc.harvard.edu/contrib/maxim/bg/index.html. The above files are from Series "D" of Maxim's file editions, renamed to CALDB convention. E. PCAD Field Distortion Coefficients V3 FILENAME: acapD1999-07-22fdcN0003.fits LOCATION: $CALDB/data/chandra/pcad/bcf/fdc/ This change only affects ASPECT L1 processing, SDP only. Provides for a platescale correction for the primary aspect camera assembly (ACA-P). F. Demotion of ACIS/HEG1 and ACIS/MEG1 LSFPARM V1 files FILENAMES: acisheg1D1999-07-22lsfparmN0001.fits acismeg1D1999-07-22lsfparmN0001.fits LOCATION: $CALDB/data/chandra/tel/grating/hetg/cpf/lsf/ THESE FILES ARE NOW MARKED "BAD" (CAL_QUAL=5) in the ACIS caldb.indx file. CIAO and other software using the index will not find the files. Also, these N0001 files are not included at all the new tar files. These files have been found to have incorrect EE_FRACS data columns in their principle HDU BINTABLES. Corrected versions are forthcoming. For now the HETG GRMF thread will point to the CANNED GRATING RMFs in the CALDB for this configuration. This demotion does NOT affect users with LETG/ACIS-S data at all. II. Technical Details A. HRC-S QE (V5) and QEU (V3) The LETG and HRC calibration groups have released new, corrected versions of the HRC-S QE and QE Uniformity. The new QE-related data are posted as follows on the Chandra CAL web pages: For the UV ION SHIELD (UVIS): http://cxc.harvard.edu/cal/Links/Hrc/CIP/SACpre/uvis_s1.v3.1.mdl http://cxc.harvard.edu/cal/Links/Hrc/CIP/SACpre/uvis_s2.v3.1.mdl http://cxc.harvard.edu/cal/Links/Hrc/CIP/SACpre/uvis_s34.v3.1.mdl http://cxc.harvard.edu/cal/Links/Hrc/CIP/SACpre/uvis_s56.v3.1.mdl and for the MCP raw QE: http://cxc.harvard.edu/cal/Links/Hrc/CIP/Flight/mcp_qe_s.v2.1.mdl These include some new sub-assembly calibrations using synchrotron radiation, among other testing results. For the QEU, flight observations of Capella, among other objects, were used to calibrate the LETG/HRC-S first-order effective area, and from that derive a self-consistent QE Uniformity for use in CIAO's calibration configuration. Affected thread: Compute LETG/HRC-S Grating ARFs http://cxc.harvard.edu/ciao/threads/mkgarf_letghrcs/ B. HRC-S EEARFs for +/- first orders These files were first promulgated by the LETG CAL group directly, available from their effective area web page at http://cxc.harvard.edu/cal/Links/Letg/User/Hrc_QE/ea_index.html#first See the second set of EEARFs below the third paragraph at this link. These files include the "bow-tie" extraction region that is included by the grating level 2 pipeline "tgextract". The values in this EEARF are less than unity, which means they degrade the effective area somewhat as per the admittance of the bow-tie extraction region. The bow-tie is used to reduce the background level in the first-order spectra. One uses these files with grating ARFs produced by CIAO's mkgarf routine, provided you are using CALDB version 2.12 or greater, until the software is modified at some future date to include the bow-tie extraction region in the calculations of GARFs or GRMFs. The Sherpa command "RSP" includes a third parameter wherein once may presently include an EEARF. Threads affected: "Compute LETG/HRC-S Grating ARFs" http://cxc.harvard.edu/ciao/threads/mkgarf_letghrcs/ and "Reading Data & Instrument Responses Into Sherpa" http://cxc.harvard.edu/ciao/threads/sherpa_spectra/#read C. Correction of CORNERS keyword value in ACIS Grade file (DATAMODE = GRADED only) The CORNERS value is now "2" and not "1" (INT4). The change affects the PHA summation values for events with grades 5 and 7 only, and reduces the PHA systematically for those events, since both adjacent pixels must be above the split threshold for the corner to be included in the sums. However, grades 5 and 7 are ordinarily filtered by default in Level 2, so this affects only users who for their particular analyses change the grade selection defaults in Level 2. SDP already uses a CORNERS value of "2" in a separate file. Soon SDP will use the CALDB grade file rather than one of its own. This will correct a previous oversight in the implementation of the CALDB data into SDP. Threads affected (trivially): Generate A New [ACIS] Level=1 Events File http://cxc.harvard.edu/ciao/threads/acisgainmap/#level1 http://cxc.harvard.edu/ciao/threads/acispixrand/#level1 http://cxc.harvard.edu/ciao/threads/acispharand/#level1 D. ACIS Background files, effective 2000-12-01 - 2001-12-01 These files are to be used for observations with start dates later than 2000-12-01T00:00:00 (TSTART>= 92016063.184 seconds), and are effective in the CALDB until the next set in the series is added. The set includes all ACIS chips in the various in-plane or out-of-plane configurations as are in fact available to ACIS. Threads affected: "ACIS Background Subtraction (Blank-Sky Files)" http://cxc.harvard.edu/ciao/threads/acisbackground/ E. NEW PCAD "CALFDC" file See the discussion on the ASPECT platescale corrections page, "Revised ACA plate scale coefficients" http://asc.harvard.edu/mta/ASPECT/aca_plate_scale/ updated as of 01/08/02. This affects Standard Data Processing (SDP) only, in the ASPECT L1 pipeline. F. Demotion of ACIS/HETG LSF parameter files The EE_FRACS columns for both the MEG1 and HEG1 files have been found to be incorrect. Hence, the thread for ACIS/HETG Grating RMFs http://cxc.harvard.edu/ciao/threads/mkgrmf_aciss/ has been modified (as of FEB 1, 2002) to point users again to the CANNED grating RMFs in the CALDB, located at $CALDB/data/chandra/tel/grating/hetg/cpf/rmf/. NOTE: LETG/ACIS-S observations are NOT affected by this change, and hence mkgrmf may still be used to generate observation-specific GRMFs using this thread.