Last modified: 8 December 2020

URL: https://cxc.cfa.harvard.edu/caldb/prop_plan/pimms/pimms.html

Cycle 23 PIMMS Effective Area Public Information

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Released as of 15 DEC 2020



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 4.13 routines mkarf for imaging aimpoint cases and mkgarf for gratings configurations, using the most current CALDB input files (CALDB 4.9.4). 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 22 (N0022) and Cycle 23 (N0023) 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 23:

CalDB Input File Uprades (since Cycle 22):

  1. 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.

  2. ACIS configurations: These have all been affected by the upgrade of the ACIS CONTAM file from version N0013 in Cycle 22 to N0014 in Cycle 23. The N0014 CONTAM file predicts a higher contamination level at approximately the start of year 2019, which decreases the relative effective area. Additionally, the TIME delay qualifier for the effective areas has been adjusted for Cycle 23 to be 15 May 2022 UTC, or 768960069.184s MET. The result is that the Cycle 23 EAs for ACIS configurations a noticeable decrease in predicted EA below 1 keV compared with Cycle 22 for both ACIS-I and ACIS-S.

  3. HRC-I configurations: A new time-varying central QE has been released for HRC-I since the previous cycle, including new annual files extending to Jan 1, 2020. The result is a significant change in HRC-I configuration EAs, with a step-characteristic at ~630 eV in these configurations, compared with cycle 22.

  4. HRC-S configurations: A new series of time-dependent QE files for HRC-S has been added to CalDB since the previous cycle. In addition, the QEU series has also been updated, with a new file effective 2019-08-22. The modified QE produces a considerable change relative to the previous cycle, as is evident from the difference plots for the HRC-S configurations. The result is a slightly decreased effective area relative to 22 below ~630 eV, but an enhanced EA above that energy.

Parameter Input Changes (versus CY22 inputs):

  1. 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.

  2. 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 23 the value is 768960069.184, which corresponds to UTC date 15 May 2022. For Cycle 22 the value was 737424069.184, corresponding to 15 May 2021. This affects all and only ACIS configurations.


TABLE 1

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 acisD1999-08-13contamN0013.fits
acisD1999-08-13contamN0014.fits
737424069.184
768960069.184
N/A N/A acisiD2019-11-14pimmsN0022.fits
acisiD2020-11-17pimmsN0023.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 acisD1999-08-13contamN0013.fits
acisD1999-08-13contamN0014.fits
737424069.184
768960069.184
N/A N/A acissD2019-11-14pimmsN0022.fits
acissD2020-11-17pimmsN0023.fits
HRC-I (7590.0, 7745.0) 8531 hrmaD1996-12-20axeffaN0008.fits hrciD2017-08-20qeN0011.fits
hrciD2020-02-20qeN0012.fits
hrciD1999-07-22qeuN0002.fits N/A N/A N/A N/A N/A hrciD2019-11-14pimmsN0022.fits
hrciD2020-11-17pimmsN0023.fits
HRC-S (2095.0, 8915.0) 9630 hrmaD1996-12-20axeffaN0008.fits hrcsD2012-03-29qeN0014.fits
hrcsD2022-01-01qeN0015.fits
hrcsD2019-02-24qeuN0012.fits
hrcsD2019-08-22qeuN0013.fits
N/A N/A N/A N/A N/A hrcsD2019-11-14pimmsN0022.fits
hrcsD2020-11-17pimmsN0023.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 acisD1999-08-13contamN0013.fits
acisD1999-08-13contamN0014.fits
737424069.184
768960069.184
N/A hetgD1996-11-01greffpr001N0007.fits acisihetg0D2019-11-14pimmsN0022.fits
acisihetg0D2020-11-17pimmsN0023.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 acisD1999-08-13contamN0013.fits
acisD1999-08-13contamN0014.fits
737424069.184
768960069.184
N/A hetgD1996-11-01greffpr001N0007.fits acisshetg0D2019-11-14pimmsN0022.fits
acisshetg0D2020-11-17pimmsN0023.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 acisD1999-08-13contamN0013.fits
acisD1999-08-13contamN0014.fits
737424069.184
768960069.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0007.fits acissheg1D2019-11-14pimmsN0022.fits
acissheg1D2020-11-17pimmsN0023.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 acisD1999-08-13contamN0013.fits
acisD1999-08-13contamN0014.fits
737424069.184
768960069.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0007.fits acisshegmeg1D2019-11-14pimmsN0022.fits
acisshegmeg1D2020-11-17pimmsN0023.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 acisD1999-08-13contamN0013.fits
acisD1999-08-13contamN0014.fits
737424069.184
768960069.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0007.fits acissmeg1D2019-11-14pimmsN0022.fits
acissmeg1D2020-11-17pimmsN0023.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 acisD1999-08-13contamN0013.fits
acisD1999-08-13contamN0014.fits
737424069.184
768960069.184
acisD2000-01-29osip_ctiN0006.fits letgD1996-11-01greffpr001N0007.fits acisiletg0D2019-11-14pimmsN0022.fits
acisiletg0D2020-11-17pimmsN0023.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 acisD1999-08-13contamN0013.fits
acisD1999-08-13contamN0014.fits
737424069.184
768960069.184
acisD2000-01-29osip_ctiN0006.fits letgD1996-11-01greffpr001N0007.fits acissletg0D2019-11-14pimmsN0022.fits
acissletg0D2020-11-17pimmsN0023.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 acisD1999-08-13contamN0013.fits
acisD1999-08-13contamN0014.fits
737424069.184
768960069.184
acisD2000-01-29osip_ctiN0006.fits letgD1996-11-01greffpr001N0007.fits acissleg1D2019-11-14pimmsN0022.fits
acissleg1D2020-11-17pimmsN0023.fits
LETG0/HRC-I (7590.0, 7745.0) 8531 hrmaD1996-12-20axeffaN0008.fits hrciD2017-08-20qeN0011.fits
hrciD2020-02-20qeN0012.fits
hrciD1999-07-22qeuN0002.fits N/A N/A N/A N/A letgD1996-11-01greffpr001N0007.fits hrciletg0D2019-11-14pimmsN0022.fits
hrciletg0D2020-11-17pimmsN0023.fits
LETG0/HRC-S (2116.9, 8850.3) 331 hrmaD1996-12-20axeffaN0008.fits hrcsD2012-03-29qeN0014.fits
hrcsD2022-01-01qeN0015.fits
hrcsD2019-02-24qeuN0012.fits
hrcsD2019-08-22qeuN0013.fits
N/A N/A N/A N/A letgD1996-11-01greffpr001N0007.fits hrcsletg0D2019-11-14pimmsN0022.fits
hrcsletg0D2020-11-17pimmsN0023.fits
LEG1/HRC-S (2116.9, 8850.3) 331 hrmaD1996-12-20axeffaN0008.fits hrcsD2012-03-29qeN0014.fits
hrcsD2022-01-01qeN0015.fits
hrcsD2019-02-24qeuN0012.fits
hrcsD2019-08-22qeuN0013.fits
N/A N/A N/A N/A letgD1996-11-01greffpr001N0007.fits hrcsleg1D2019-11-14pimmsN0022.fits
hrcsleg1D2020-11-17pimmsN0023.fits
LEGHI/HRC-S (2116.9, 8850.3) 331 hrmaD1996-12-20axeffaN0008.fits hrcsD2012-03-29qeN0014.fits
hrcsD2022-01-01qeN0015.fits
hrcsD2019-02-24qeuN0012.fits
hrcsD2019-08-22qeuN0013.fits
N/A N/A N/A N/A letgD1996-11-01greffpr001N0007.fits hrcsleghiD2019-11-14pimmsN0022.fits
hrcsleghiD2020-11-17pimmsN0023.fits

Notes for Table 1:

None.

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