Cycle 21 PIMMS Effective Area Public Information
Released as of 13 DEC 2018
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 routines.
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 4.11 routines mkarf for imaging aimpoint cases and mkgarf for gratings configurations, using the most current CALDB input files (CALDB 4.8.2). 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 20 (N0020) and Cycle 21 (N0021) 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 21:
CalDB Input File Uprades (since Cycle 20):
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AIMPOINT Configurations: All the grids for the aimpoint configurations have changed to 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. This means that the ACIS aimpoint and zeroth order grids all have 8192 points. For HRC, the energy grids include 16384 points. These have been changed 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: These have all been affected by the upgrade of the ACIS CONTAM file from version N0010 in cycle 20 to N0012 in Cycle 21. The N0012 CONTAM file predicts a lower contamination level after the start of year 2018, which increases the relative effective area. Additionally, the TIME delay qualifier for the effective areas has been adjusted for Cycle 21 to be 15 May 2020 UTC, or 705888069.184s MET. The result is that the Cycle 21 EAs for ACIS configurations show up to 100% increase in predicted EA near the carbon edge compared with Cycle 20, and the difference decreases to 10% at 1 keV, and becomes negligible above 2 keV, as expected for the contamination effect.
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HRC-I configurations: The HRC-I QE has been upgraded to a time-dependent set of files version N0011with the last file becoming effective 2017-08-20 UTC. The file produces a variable change in the QE (and hence EA) from the previous version N0010 which was used in the HRC-I Cycle 20 EA configurations. The EA is reduced by up to 20% over 0.06 - 0.652 keV, but has no relative effect at higher energies.
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HRC-S configurations: There has been an update to the time-dependent QE Uniformity for HRC-S which produces a minor change to the CY21 HRC-S EAs compared with the CY20 EAs. The effect is overall less than 2.5 %, and is less than 1% at the aimpoint position. (The HRC-S QEU is variable as a function of location along the length of the detector arrray, and is therefore wavelength-dependent.) Note that the apparent changes in the HRC-S Aimpoint EA are due mainly to the update in the energy grid for that configuration.
Parameter Input Changes (versus CY20 inputs):
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Imaging aimpoints:Due to the thermal cycling of the Chandra Aspect Camera, the aimpoint drift has become irregular, and an operational scheme has been adopted to fix targets dynamically at the desired location. This results in a permanent aimpoint location for each chip as a matter of course (which may be changed programatically if necessary, but not due to drift. See the Table below, and the Proposers Observatory Guide (POG) Table 6.4. The permanent aim point locations were set for the Cycle 18 release, and remain so for the current cycle.
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ACIS CONTAM time-delay parameter: The CIAO ARF- and GARF-generating routines employ a time-delay option in the "detsubsys" parameter specification, wherein a TT date value in seconds may be entered to set the date for the time-dependent CONTAM calculations. For Cycle 21 the value is 705888069.184, which corresponds to UTC date 15 May 2020. For Cycle 20 the value was 674265669.184, corresponding to 15 May 2019. This affects all and only ACIS configurations.
| Configuration | (CHIPX, CHIPY) | ObsID Used | HRMA | QE | QEU | ACIS FI DEAD AREA | ACIS CONTAM | CONTAM TIME DELAY | ACIS OSIP | GREFF | CALDB Filenames |
| ACIS-I | (970.0, 975.0) | 9768 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0012.fits |
674265669.184 705888069.184 |
N/A | N/A |
acisiD2017-11-29pimmsN0020.fits
acisiD2018-11-20pimmsN0021.fits |
| ACIS-S | (210.0, 520.0) | 9300 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0012.fits |
674265669.184 705888069.184 |
N/A | N/A |
acissD2017-11-29pimmsN0020.fits
acissD2018-11-20pimmsN0021.fits |
| HRC-I | (7590.0, 7745.0) | 8531 | hrmaD1996-12-20axeffaN0008.fits | hrciD1999-07-22qeN0010.fits hrciD2017-08-20qeN0011.fits |
hrciD1999-07-22qeuN0002.fits | N/A | N/A | N/A | N/A | N/A |
hrciD2017-11-29pimmsN0020.fits
hrciD2018-11-20pimmsN0021.fits |
| HRC-S | (2095.0, 8915.0) | 9630 | hrmaD1996-12-20axeffaN0008.fits | hrcsD2012-03-29qeN0014.fits | hrcsD2019-01-01qeuN0008.fits hrcsD2018-05-27qeuN0010.fits |
N/A | N/A | N/A | N/A | N/A |
hrcsD2017-11-29pimmsN0020.fits
hrcsD2018-11-20pimmsN0021.fits |
| HETG0/ACIS-I | (970.0, 975.0) | 9768 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0012.fits |
674265669.184 705888069.184 |
N/A | hetgD1996-11-01greffpr001N0007.fits |
acisihetg0D2017-11-29pimmsN0020.fits
acisihetg0D2018-11-20pimmsN0021.fits |
| HETG0/ACIS-S | (211.2, 369.3) | 7280 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0012.fits |
674265669.184 705888069.184 |
N/A | hetgD1996-11-01greffpr001N0007.fits |
acisshetg0D2017-11-29pimmsN0020.fits
acisshetg0D2018-11-20pimmsN0021.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 | acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0012.fits |
674265669.184 705888069.184 |
acisD2000-01-29osip_ctiN0006.fits | hetgD1996-11-01greffpr001N0007.fits |
acissheg1D2017-11-29pimmsN0020.fits
acissheg1D2018-11-20pimmsN0021.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 | acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0012.fits |
674265669.184 705888069.184 |
acisD2000-01-29osip_ctiN0006.fits | hetgD1996-11-01greffpr001N0007.fits |
acisshegmeg1D2017-11-29pimmsN0020.fits
acisshegmeg1D2018-11-20pimmsN0021.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 | acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0012.fits |
674265669.184 705888069.184 |
acisD2000-01-29osip_ctiN0006.fits | hetgD1996-11-01greffpr001N0007.fits |
acissmeg1D2017-11-29pimmsN0020.fits
acissmeg1D2018-11-20pimmsN0021.fits |
| LETG0/ACIS-I | (970.0, 975.0) | 9768 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0012.fits |
674265669.184 705888069.184 |
acisD2000-01-29osip_ctiN0006.fits | letgD1996-11-01greffpr001N0007.fits |
acisiletg0D2017-11-29pimmsN0020.fits
acisiletg0D2018-11-20pimmsN0021.fits |
| LETG0/ACIS-S | (210.0 520.0) | 10662 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0012.fits |
674265669.184 705888069.184 |
acisD2000-01-29osip_ctiN0006.fits | letgD1996-11-01greffpr001N0007.fits |
acissletg0D2017-11-29pimmsN0020.fits
acissletg0D2018-11-20pimmsN0021.fits |
| LEG1/ACIS-S | (210.0 520.0) | 10662 | hrmaD1996-12-20axeffaN0008.fits | acisD1997-04-17qeN0006.fits | acisD2010-02-01qeuN0007.fits | acisD1999-09-16dead_areaN0001.fits | acisD1999-08-13contamN0010.fits acisD1999-08-13contamN0012.fits |
674265669.184 705888069.184 |
acisD2000-01-29osip_ctiN0006.fits | letgD1996-11-01greffpr001N0007.fits |
acissleg1D2017-11-29pimmsN0020.fits
acissleg1D2018-11-20pimmsN0021.fits |
| LETG0/HRC-I | (7590.0, 7745.0) | 8531 | hrmaD1996-12-20axeffaN0008.fits | hrciD1999-07-22qeN0010.fits hrciD2017-08-20qeN0011.fits |
hrciD1999-07-22qeuN0002.fits | N/A | N/A | N/A | N/A | letgD1996-11-01greffpr001N0007.fits |
hrciletg0D2017-11-29pimmsN0020.fits
hrciletg0D2018-11-20pimmsN0021.fits |
| LETG0/HRC-S | (2116.9, 8850.3) | 331 | hrmaD1996-12-20axeffaN0008.fits | hrcsD2012-03-29qeN0014.fits | hrcsD2019-01-01qeuN0008.fits hrcsD2018-05-27qeuN0010.fits |
N/A | N/A | N/A | N/A | letgD1996-11-01greffpr001N0007.fits |
hrcsletg0D2017-11-29pimmsN0020.fits
hrcsletg0D2018-11-20pimmsN0021.fits |
| LEG1/HRC-S | (2116.9, 8850.3) | 331 | hrmaD1996-12-20axeffaN0008.fits | hrcsD2012-03-29qeN0014.fits | hrcsD2019-01-01qeuN0008.fits hrcsD2018-05-27qeuN0010.fits |
N/A | N/A | N/A | N/A | letgD1996-11-01greffpr001N0007.fits |
hrcsleg1D2017-11-29pimmsN0020.fits
hrcsleg1D2018-11-20pimmsN0021.fits |
| LEGHI/HRC-S | (2116.9, 8850.3) | 331 | hrmaD1996-12-20axeffaN0008.fits | hrcsD2012-03-29qeN0014.fits | hrcsD2019-01-01qeuN0008.fits hrcsD2018-05-27qeuN0010.fits |
N/A | N/A | N/A | N/A | letgD1996-11-01greffpr001N0007.fits |
hrcsleghiD2017-11-29pimmsN0020.fits
hrcsleghiD2018-11-20pimmsN0021.fits |
Notes for Table 1:
None.