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CalDB PUBLIC Release Notes
Effective Date: (UTC) 2006-12-15T14:00:00
Public Release Date: 15 December 2006
Version: 3.3.0
Release Type: SDP + PUBLIC

I. Introduction

CalDB 3.3.0 is an significant upgrade to the Chandra Calibration Database (CalDB), which includes new -120C ACIS BI chip responses and CTI-corrections, new corresponding ACIS QE Uniformities and Order-sorting tables (OSIPs), new response input data for mkacisrmf, and newly released HRC-I time-dependent gain corrections. These installations require that users upgrade to CIAO 3.4 in order that the correct calibration files will be selected. Likewise, CIAO 3.4 requires users to upgrade to CalDB 3.3.0 to make full use of its new capabilities.

The new ACIS -120C response-related files such as CTI, T_GAIN, GAIN, P2_RESP, and QEU are part of the "ACIS N0006 responses suite," and as such may be referred to collectively with that epithet. The N0006 suite differs from the N0005 suite in that the new BI chip CTI corrections have been added to it, and the ACIS QE Uniformity file has now been reconsidered as part of the suite.

II. Summary of Changes

A. ACIS -120C BI chip CTI corrections (parallel and serial)
LOCATION: $CALDB/data/chandra/acis/bcf/cti/
FILENAMES:    acisD2000-01-29ctiN0006.fits

The trap density maps for the SERIAL and PARALLEL CTI correction of the ACIS BI chips (ACIS-5 (S1) and ACIS-7 (S3)) have been added to the FI chip parallel CTI trap maps released in version N0005 of these files.

These new N0006 CTI files will be used as the default in Standard Data Processing (SDP), for the cases of FAINT or VFAINT datamode settings,  with the release of DS 7.6.10 later in December 2006. GRADED datamodes you may be aware, may not be CTI-corrected using the current algorithm.

PIPES/TOOLS affected:
ACIS L1 pipeline and CIAO 3.4 tool "acis_process_events"

THREADS affected:
"Apply the ACIS CTI Correction"
"Create a New Level=2 Event File"

B. ACIS -120C Time-dependent Gain Corrections (T_GAIN) for BI-CTI-corrected events, version N0006
LOCATION:    $CALDB/data/chandra/acis/bcf/t_gain/
FILENAMES:    acisD<yyyy-mm-dd>t_gainN0006.fits (for T_GAIN Epochs #1 - #27)
              acisD2006-08-01t_gain_biN0002.fits (projected flat file for Epoch #28)

The time-dependent gain corrections will be altered if CTI-correction has been applied to the ECS data that have been selected in the T_GAIN derivation. Hence, although the FI chip corrections are unaltered in this release, the BI chip corrections are now separate from the N0005 T_GAIN file set. Both the N0005 and the N0006 suite of T_GAIN data files will be maintained for the time being, at least until the BI CTI corrections are accepted as the new standard by the Chandra community at large.

PIPES/TOOLS affected:
ACIS L1 pipeline and CIAO 3.4 tool "acis_process_events"

THREADS affected:
"Create a New Level=2 Event File"
"Apply the ACIS Time-Eependent Gain Correction"
C. ACIS -120C gain (DET_GAIN) N0006
LOCATION:    $CALDB/data/chandra/bcf/gain/
FILENAME:    acisD2000-01-29gain_ctiN0006.fits

With the advent of the new CTI corrections for the BI chips S1 and S3, there are new gain calculations to apply to the data as well.

PIPES/TOOLS affected:
ACIS L1 pipeline and CIAO 3.4 tool "acis_process_events"

THREADS affected:
"Create a New Level=2 Event File"
"Apply an ACIS Gain Map"

D. ACIS -120C Phase 2 Reponses file (P2_RESP) N0006
LOCATION:    $CALDB/data/chandra/acis/cpf/p2_resp/
FILENAME:    acisD2000-01-29p2_respN0006.fits

The data for the FI chips in the new file are all identical to those included in the N0005 version, released with CalDB 3.2.0 in November 2005. The BI chips data for all three of 1) the idealized pre-CTI response, the CTI-induced Gaussian broadening, and the small tweaks included in the GAIN_CORR extension for the BI chips, have each been updated to include our most refined RMF input data for mkacisrmf.

PIPES/TOOLS affected:
CIAO 3.4 tool mkacisrmf
Offline OSIP file generator routine mkosip.sl

THREADS affected:
"Creating ACIS RMFs with mkacisrmf"

E. ACIS -120C QE Uniformity (QEU) Files N0005, N0006
LOCATION:    $CALDB/data/chandra/acis/bcf/qe/
FILENAMES:   acisD2000-01-29qeuN0005.fits

We have upgraded the ACIS QEU file for -120C operating temperatures for the two CTI correction configurations. The N0005 file applies to the case where only the FI chips are CTI-corrected, namely on the Chandra data archive where Repro 3 has been running. The N0006 file will become the new standard when the BI chip CTI corrections are done in SDP; Users may also make use of it with the N0006 responses suite, if they reprocess their ACIS L1 events files with CIAO 3.4/CalDB 3.3.0.

Specifically what has been updated in the files is that the QEU for the ACIS-4, 8, and 9 chips has been reset the same as the ACIS-6 chip in the old version N0002 QEU (acisD2000-01-29qeuN0002.fits, released with CalDB 3.2.0 in Nov. 2005). The old file had the uniformity set to unity for chips 4, 8, and 9. Additionally, in the N0006 QEU, the recovery of events on the BI chips which had previously migrated from good to bad grades, requires that the Uniformity affect be decreased by a few percent in the CTI-corrected case. Hence the QE appears to be more uniform with the CTI correction applied, as is to be expected.

PIPES/TOOLS affected:
CIAO 3.4 tools mkarf, mkexpmap (mkinstmap), mkwarf, mkgarf
CIAO script fullgarf

THREADS affected:
Any threads that use the above tools

F. ACIS -120C OSIP files N0005, N0006
LOCATION:    $CALDB/data/chandra/acis/cpf/osip/
FILENAMES:    acisD2000-01-29osip_ctiN0005.fits

The order-sorting and integrated probability tables (OSIP) had not been upgraded since the introduction of the FI chip CTI corrections or the new phase 2 response generator (mkacisrmf). This has now been rectified, with the introduction of two new OSIP files, one for the case of CTI-correction being applied to Chips 4, 6, 8, and 9, and the other for all six ACIS-S chips being CTI-corrected.

PIPES/TOOLS affected:
CIAO/SDP Grating L1.5 pipeline tg_resolve_events
CIAO tool mkgarf and script fullgarf

THREADS affected:
"Create and Order-sorting Image"
"Compute ACIS-S/HETG Grating Arfs"
"Computer ACIS-S/LETG Grating Arfs"

G. ACIS Quantum Efficiency N0006
LOCATION:    $CALDB/data/chandra/acis/bcf/qe/
FILENAMES:    acisD1997-04-17qeN0006.fits

A small correction has been included for all 10 chips near the Si-K absorption edge, which properly accounts for the Si-K escape peak effect. This adjustment consists of a narrow -4% adjustment at ~1800 ev of the QE.

PIPES/TOOLS affected: 
CIAO 3.4 tools mkarf, mkexpmap (mkinstmap), mkwarf, mkgarf
CIAO script fullgarf

THREADS affected:
Any threads that use the above tools

H. ACIS Dead Area File version N0001
LOCATION:    $CALDB/data/chandra/acis/bcf/dead_area/
FILENAME:    acisD2000-09-16dead_areaN0001.fits

The dead area affect on the ACIS FI chips (not the BI chips) has been calibrated from an I3 measurement of a cluster. The effect accounted for here is from cosmic rays which strike the detector and render a portion of it dead for an entire frame. There is a CHIPY dependence, giving a constant correction for all chips at a given CHIPY, and the correction ranges from -2.5% at the readout to -4% at the top of the chip. In CIAO 3.4, the application of the dead area correction is NOT the default; users must pset the "dafile" and "pbkfile" parameters in the particular tool they are using.

PIPES/TOOLS affected: 
CIAO 3.4 tools mkarf, mkexpmap (mkinstmap), mkwarf, mkgarf
CIAO script fullgarf

THREADS affected:
Any threads that use the above tools

I. HRC-I Time-dependent Gain Maps (GMAP)
LOCATION:    $CALDB/data/chandra/hrc/bcf/gain/
FILENAMES:     hrciD1999-10-04gainN0002.fits

The HRC calibration team has released a set of seven new GMAP files to account for the long-recognized HRC-I gain decline. These maps are space approximately one year apart, and allow a more accurate determination of hardness ratios and quatile color-color grids.

J. HRC-S Response Matrix Function (RMF) version N0001
LOCATION:    $CALDB/data/chandra/hrc/cpf/rmf/
FILENAME:    hrcsD1999-07-22rmfN0001.fits

The quantile analysis and hardness ratio estimates that were introduced to the user community during 2005 have now been added for the HRC-S in imaging mode. This RMF is derived primarily for HRC-S2, the central plate, but may be applied more generally to the full array with somewhat less fidelity on the outer plates HRC-S1 and HRC-S3.

K. CY09 PIMMS Effective Areas (PIMMS_EA)
LOCATION:    $CALDB/data/chandra/acis/cpf/pimms/
FILES:        acisiD2006-10-26pimmsN0009.fits
LOCATION:    $CALDB/data/chandra/hrc/cpf/pimms/
FILES:        hrciD2006-10-26pimmsN0009.fits
LOCATION:    $CALDB/data/chandra/tel/grating/hetg/cpf/pimms/
FILES:        acisihetg0D2006-10-26pimmsN0009.fits
LOCATION:    $CALDB/data/chandra/tel/grating/letg/cpf/pimms/
FILES:        acisiletg0D2006-10-26pimmsN0009.fits

TOOLS affected: PIMMS count rate estimator for CY09 proposal release
Chandra CY09 Effective Area Viewer 

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