Cycle 25 PIMMS Effective Area Public Information
Released as of 15 DEC 2022
The Chandra effective areas are built for sixteen configurations implemented in the PIMMS EA viewer and count rate calculator facility. Four of the configurations are for the default aim-point positions for each of the four detector arrays aboard Chandra, specifically the ACIS-I, ACIS-S, HRC-I and HRC-S detectors.
The other twelve configurations involve one or the other of the transmission gratings. For the HETG/ACIS-S configurations the default SIM_Z positions do not correspond to the above aim point settings, but instead are offset to minimize the ACIS CTI effect. A default SIM_Z offset of -3.0 mm (in the direction of the readouts) is used for HETG/ACIS-S.
As in previous years, model observations have been selected so that the zeroth order ARFs, as well as the first order GARFs will correspond to the appropriate positions on the ACIS-S array. The same is true for the LETG/HRC-S configuration, where the default zeroth order position does not necessarily coincide with the default imaging aim point.
PIMMS effective area (EA) files are built using model observations (OBSIDs) with standard/default detector and SIM_Z configurations with the CIAO 4.15 routines mkarf for imaging aimpoint cases and mkgarf for gratings configurations, using the most current CALDB input files (CALDB 4.10.2). The following table gives the input CALDB file information used by mkarf or mkgarf to generate the respective effective area files (as ARFs) for the Cycle 24 (N0024) and Cycle 25 (N0025) proposal cycles. Plots of the PIMMS effective areas may be viewed at the PIMMS Effective Area Data page. You may also use the automated Chandra Effective Area Viewer.
PIMMS Input Data and Procedure Changes for Cycle 25:
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AIMPOINT Configurations: ENERGY GRIDS All the grids for the aimpoint configurations match the default energy grid of the LETG first order for that detector array; for the HRC-I, the grid corresponds to the LETG/HRC-S first order default grid. Hence, for ACIS configurations, the aimpoint and zeroth order grids all have 8192 points. For HRC, the energy grids include 16384 points. The grids were changed for Cycle 21 in December 2018, to eliminate interpolation errors that occur when comparing spectra (and associated count rates) when comparing or calculating results across configurations.
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ACIS configurations: The ACIS-I and ACIS-S aimpoints have been changed slightly due to the adoption of new larger dither default parameters for ACIS. The changes are noted in the table below for the ACIS AIMPOINT configurations, as well as the ACIS/Grating Zeroth Order configurations. The ACIS CONTAM model file has also been upgraded from version N0014 to N0015. This is coupled with the new time-delay setting that occurs with each succeeding proposal cycle. Specifically, the TIME delay qualifier for the ACIS effective areas has been adjusted for Cycle 25 to be 15 May 2024 UTC, or 832118469.184s MET. The result is that the Cycle 25 EAs for ACIS configurations show a still further decrease in predicted EA below 1 keV compared with Cycle 24 for both ACIS-I and ACIS-S. The relative reduction at the carbon edge is -200%, while at the oxygen K-edge, it is about -140%.
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HRC-I configurations: There are no changes in PIMMS for HRC-I configurations between Cycle 25 and Cycle 24. Hence the difference traces for these two configurations (HRC-I AIMPOINT and HRC-I/LETG0) are zero.
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HRC-S configurations: There is only one change in calibration inputs for the HRC-S configurations, specifically the upgrade in the HRC-S QEU from version N0015 to N0016, and the addition of an extra file effective on 2021-09-02. The QEU change affects only the longer wavelengths (lower energies) in the first order and higher orders of the HRC-S/LETG configurations. Hence the HRC-S AIMPOINT and Zeroth order configurations are unaffected, and show zero differences from Cycle 24 in the difference plots. For the LEG1/HRC-S configuration, the new QEU gives an irregular correction versus photon energy from 0.06-~0.235 keV between +1% and -2% relative to the previous cycle.
| Configuration | (CHIPX, CHIPY) | ObsID Used | HRMA | QE | QEU | ACIS FI DEAD AREA | ACIS CONTAM | CONTAM TIME DELAY | ACIS OSIP | GREFF | CALDB Filenames |
| ACIS-I |
(970.00, 975.00) (953.74, 958.74) |
9768 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
800496069.184 832118469.184 |
N/A | N/A |
acisiD2021-11-03pimmsN0024.fits
acisiD2022-11-10pimmsN0025.fits |
| ACIS-S |
(210.00, 520.00) (193.74, 520.00) |
9300 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
800496069.184 832118469.184 |
N/A | N/A |
acissD2021-11-03pimmsN0024.fits
acissD2022-11-10pimmsN0025.fits |
| HRC-I | (7590.0, 7745.0) | 8531 | hrmaD1996-12-20axeffaN0008.fits | hrciD2021-02-16qeN0013.fits | hrciD1999-07-22qeuN0002.fits | N/A | N/A | N/A | N/A | N/A |
hrciD2021-11-03pimmsN0024.fits
hrciD2022-11-10pimmsN0025.fits |
| HRC-S | (2195.0, 8915.0) | 9630 | hrmaD1996-12-20axeffaN0008.fits | hrcsD2021-05-14qeN0016.fits | hrcsD2021-05-14qeuN0015.fits hrcsD2021-09-02qeuN0016.fits |
N/A | N/A | N/A | N/A | N/A |
hrcsD2021-11-03pimmsN0024.fits
hrcsD2022-11-10pimmsN0025.fits |
| HETG0/ACIS-I |
(970.00, 975.00) (953.74, 958.74) |
9768 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
800496069.184 832118469.184 |
N/A | hetgD1996-11-01greffpr001N0007.fits |
acisihetg0D2021-11-03pimmsN0024.fits
acisihetg0D2022-11-10pimmsN0025.fits |
| HETG0/ACIS-S |
(210.00, 520.00) (193.74, 520.00) |
7280 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
800496069.184 832118469.184 |
N/A | hetgD1996-11-01greffpr001N0007.fits |
acisshetg0D2021-11-03pimmsN0024.fits
acisshetg0D2022-11-10pimmsN0025.fits |
| HEG1/ACIS-S | (211.2, 369.3) | 7280 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
800496069.184 832118469.184 |
acisD2000-01-29osip_ctiN0006.fits | hetgD1996-11-01greffpr001N0007.fits |
acissheg1D2021-11-03pimmsN0024.fits
acissheg1D2022-11-10pimmsN0025.fits |
| HEGMEG1/ACIS-S | (211.2, 369.3) | 7280 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
800496069.184 832118469.184 |
acisD2000-01-29osip_ctiN0006.fits | hetgD1996-11-01greffpr001N0007.fits |
acisshegmeg1D2021-11-03pimmsN0024.fits
acisshegmeg1D2022-11-10pimmsN0025.fits |
| MEG1/ACIS-S | (211.2, 369.3) | 7280 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
800496069.184 832118469.184 |
acisD2000-01-29osip_ctiN0006.fits | hetgD1996-11-01greffpr001N0007.fits |
acissmeg1D2021-11-03pimmsN0024.fits
acissmeg1D2022-11-10pimmsN0025.fits |
| LETG0/ACIS-I |
(970.00, 975.00) (953.74, 958.74) |
9768 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
800496069.184 832118469.184 |
N/A | letgD1996-11-01greffpr001N0007.fits |
acisiletg0D2021-11-03pimmsN0024.fits
acisiletg0D2022-11-10pimmsN0025.fits |
| LETG0/ACIS-S | (210.00, 520.00) (193.74, 520.00) |
10662 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
800496069.184 832118469.184 |
N/A | letgD1996-11-01greffpr001N0007.fits |
acissletg0D2021-11-03pimmsN0024.fits
acissletg0D2022-11-10pimmsN0025.fits |
| LEG1/ACIS-S | (210.00, 520.00) (193.74, 520.00) |
10662 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0014.fits acisD1999-08-13contamN0015.fits |
800496069.184 832118469.184 |
acisD2000-01-29osip_ctiN0006.fits | letgD1996-11-01greffpr001N0007.fits |
acissleg1D2021-11-03pimmsN0024.fits
acissleg1D2022-11-10pimmsN0025.fits |
| LETG0/HRC-I | (7590.0, 7745.0) | 8531 | hrmaD1996-12-20axeffaN0008.fits | hrciD2021-02-16qeN0013.fits | hrciD1999-07-22qeuN0002.fits | N/A | N/A | N/A | N/A | letgD1996-11-01greffpr001N0007.fits |
hrciletg0D2021-11-03pimmsN0024.fits
hrciletg0D2022-11-10pimmsN0025.fits |
| LETG0/HRC-S | (2116.9, 8850.3) | 331 | hrmaD1996-12-20axeffaN0008.fits | hrcsD2021-05-14qeN0016.fits | hrcsD2021-05-14qeuN0015.fits hrcsD2021-09-02qeuN0016.fits |
N/A | N/A | N/A | N/A | letgD1996-11-01greffpr001N0007.fits |
hrcsletg0D2021-11-03pimmsN0024.fits
hrcsletg0D2022-11-10pimmsN0025.fits |
| LEG1/HRC-S | (2116.9, 8850.3) | 331 | hrmaD1996-12-20axeffaN0008.fits | hrcsD2021-05-14qeN0016.fits | hrcsD2021-05-14qeuN0015.fits hrcsD2021-09-02qeuN0016.fits |
N/A | N/A | N/A | N/A | letgD1996-11-01greffpr001N0007.fits |
hrcsleg1D2021-11-03pimmsN0024.fits
hrcsleg1D2022-11-10pimmsN0025.fits |
| LEGHI/HRC-S | (2116.9, 8850.3) | 331 | hrmaD1996-12-20axeffaN0008.fits | hrcsD2021-05-14qeN0016.fits | hrcsD2021-05-14qeuN0015.fits hrcsD2021-09-02qeuN0016.fits |
N/A | N/A | N/A | N/A | letgD1996-11-01greffpr001N0007.fits |
hrcsleghiD2021-11-03pimmsN0024.fits
hrcsleghiD2022-11-10pimmsN0025.fits |
Notes for Table 1:
None.