Chandra Calibration StatusChandra Calibration StatusSummarySummary

1.1. The gratings and mirrors are very well calibrated at this time and there are no The gratings and mirrors are very well calibrated at this time and there are no time-dependent effects as far as we can tell.time-dependent effects as far as we can tell.

2.2. Most activities in the calibration group are centered on improving the calibration Most activities in the calibration group are centered on improving the calibration of the detectors and monitoring the time-dependence response of the detectors.of the detectors and monitoring the time-dependence response of the detectors.

3.3. At present we have a single time-independent QE for each ACIS chip and HRC At present we have a single time-independent QE for each ACIS chip and HRC MCP, however, the transmission of the contaminate on ACIS is time-dependent.MCP, however, the transmission of the contaminate on ACIS is time-dependent.

4.4. The spectral response of both ACIS detectors and both HRC detectors is also The spectral response of both ACIS detectors and both HRC detectors is also treated in a time-independent manner.treated in a time-independent manner.

5.5. The ACIS gains are calibrated every 3 months and the HRC gains are calibrated The ACIS gains are calibrated every 3 months and the HRC gains are calibrated once per year.once per year.

6.6. There are two sets of trap maps for each ACIS FI chip (one set for the first 4 There are two sets of trap maps for each ACIS FI chip (one set for the first 4 years and one set for the second 4 years) and only one set of trap maps for the years and one set for the second 4 years) and only one set of trap maps for the ACIS BI chips.ACIS BI chips.

Calibration Updates Since the Last CUC MeetingCalibration Updates Since the Last CUC Meeting

ACISACIS

1.1. Gain correction files for epochs 25 and 26 (Nov 2005-May 2006) were Gain correction files for epochs 25 and 26 (Nov 2005-May 2006) were released in CALDB 3.2.4 on Nov. 7, 2006.released in CALDB 3.2.4 on Nov. 7, 2006.

2.2. A set of cti-corrected (serial and parallel) calibration products for the BI A set of cti-corrected (serial and parallel) calibration products for the BI chips at T=-120 C was released in CALDB 3.3 on Dec. 18, 2006. These chips at T=-120 C was released in CALDB 3.3 on Dec. 18, 2006. These products include: trap maps, QE maps, response files, and OSIP files.products include: trap maps, QE maps, response files, and OSIP files.

3.3. A revised version of the ACIS QE with corrections near the SI-K edge was A revised version of the ACIS QE with corrections near the SI-K edge was released in CALDB 3.3released in CALDB 3.3

4.4. Gain correction files for epoch 27 (May 2006-Nov 2006) were released in Gain correction files for epoch 27 (May 2006-Nov 2006) were released in CALDB 3.3CALDB 3.3

5.5. Gain correction files for epoch 28 (Dec. 2006-Feb. 2007 will be Gain correction files for epoch 28 (Dec. 2006-Feb. 2007 will be released in CALDB 3.4released in CALDB 3.4

6.6. Updates to the standard set of ACIS background images will be Updates to the standard set of ACIS background images will be released in CALDB 3.4.released in CALDB 3.4.

HRCHRC

1.1. A set of gain correction files (one for each year) was released in A set of gain correction files (one for each year) was released in CALDB 3.3CALDB 3.3

2.2. A rmf for the HRC-S was released in CALDB 3.3. This is A rmf for the HRC-S was released in CALDB 3.3. This is required to make energy invariant hardness ratio images.required to make energy invariant hardness ratio images.

3.3. Further refinements to the set of HRC-I gain correction files will Further refinements to the set of HRC-I gain correction files will be released in CLDB 3.4.be released in CLDB 3.4.

HRMAHRMA

1.1. A verified Linux version (phase 1.0) of the SAOSAC software A verified Linux version (phase 1.0) of the SAOSAC software was delivered to Data Systems in Feb. for integration into Level was delivered to Data Systems in Feb. for integration into Level III processing.III processing.

2.2. A more portable version (phase 2.0) of the SAOsac raytrace A more portable version (phase 2.0) of the SAOsac raytrace software will be available to the public in May.software will be available to the public in May.

3.3. A memo was posted on the calibration web pages describing A memo was posted on the calibration web pages describing the drift of the optical axis since launch.the drift of the optical axis since launch.

LETGLETG

1.1. An updated HRC-S QE with correction near the O-K edge is An updated HRC-S QE with correction near the O-K edge is scheduled for release in CALDB 3.4.scheduled for release in CALDB 3.4.

HETGHETG

1.1. Updated OSIP files (required for cti-corrected data for the BI Updated OSIP files (required for cti-corrected data for the BI chips) were released in CALDB 3.3chips) were released in CALDB 3.3

Current Calibration ActivitiesCurrent Calibration ActivitiesACISACIS

1.1. Improve graded mode calibration which cannot be cti-corrected Improve graded mode calibration which cannot be cti-corrected in the same way as faint mode datain the same way as faint mode data..

2.2. Improve CC mode calibration. This primarily relates to gratings Improve CC mode calibration. This primarily relates to gratings data.data.

3.3. Improve calibration at T=-110 C.Improve calibration at T=-110 C.

4.4. Fitting the ECS data over the course of the mission shows that Fitting the ECS data over the course of the mission shows that there has been an increase in the width of the lines by 15-35 eV there has been an increase in the width of the lines by 15-35 eV (sigma). A metric is being devised to signal when a new set of (sigma). A metric is being devised to signal when a new set of trap maps will be necessary.trap maps will be necessary.

5.5. Possible temperature-dependent cti-corrections. Possible temperature-dependent cti-corrections.

6.6. Possible revisions to the contamination model.Possible revisions to the contamination model.

ACIS Flight GradesACIS Flight Grades

Graded Mode CalibrationGraded Mode Calibration

Line width vs. time at Al-KaLine width vs. time at Al-Ka

Line width vs. time at Mn-KaLine width vs. time at Mn-Ka

HRCHRC

1.1. Update the HRC-I de-gap map using the AO8 raster scan of Update the HRC-I de-gap map using the AO8 raster scan of Capella.Capella.

2.2. Update the low energy HRC-I QE based on the recent Update the low energy HRC-I QE based on the recent LETG/HRC-I observations of HZ43.LETG/HRC-I observations of HZ43.

3.3. Update the HRC-I QE map using the off-axis observations of Update the HRC-I QE map using the off-axis observations of RXJ1856.RXJ1856.

LETGLETG

1.1. Generate a set of finer grid time-dependent gain correction files (one per Generate a set of finer grid time-dependent gain correction files (one per year).year).

2.2. Improve the HRC-S QE below the C-K edge.Improve the HRC-S QE below the C-K edge.

3.3. Investigate the cause of the 5% drop in count rate in the LETG/HRC-S Investigate the cause of the 5% drop in count rate in the LETG/HRC-S observations of HZ43 at low energies (i.e., on the outer MPCs).observations of HZ43 at low energies (i.e., on the outer MPCs).

4.4. Derive an improved pulse-height-based background rejection filter using Derive an improved pulse-height-based background rejection filter using the fine resolution time-dependent gain corrections.the fine resolution time-dependent gain corrections.

5.5. Further improve the HRC-S de-gap coefficients tables to include empirical Further improve the HRC-S de-gap coefficients tables to include empirical corrections from emission line and continuum sources.corrections from emission line and continuum sources.

6.6. Incorporate the non-linearity in the LETG/HRC-S dispersion relation into Incorporate the non-linearity in the LETG/HRC-S dispersion relation into the line response function.the line response function.

LETG/HRC-S Observations of HZ43LETG/HRC-S Observations of HZ43

HETGHETG

1.1. Use HETG/ACIS-S data taken in CC mode to improve CC mode Use HETG/ACIS-S data taken in CC mode to improve CC mode calibration.calibration.

2.2. Improve higher order efficiencies.Improve higher order efficiencies.

HRMAHRMA

1.1. Finish analysis of ACIS piled-up observations and post a memo on Finish analysis of ACIS piled-up observations and post a memo on the calibration web pages.the calibration web pages.

2.2. Continue development of the Linux version of the raytrace softwareContinue development of the Linux version of the raytrace software

3.3. Release the enclosed count fraction (ECFs) from elliptical rather Release the enclosed count fraction (ECFs) from elliptical rather than circular apertures.than circular apertures.