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Last modified: 9 December 2016

URL: http://cxc.harvard.edu/caldb/prop_plan/pimms/pimms.html

Cycle 19 PIMMS Effective Area Public Information

Return to: PIMMS Index

Released as of 13 DEC 2016



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. Cycle 19.

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.

New for LETG/ACIS-S: The LETGS calibration team has elected to set the default SIM_Z offset from -8.0 mm (as in Cycle 17 and before) to 0.0 mm for Cycle 19, in order to minimize the contamination effect for the LETG/ACIS-S configuration. This new offset was implemented in the determination of the Cycle 18 LETG/ACIS-S PIMMS effective areas. For Cycle 19, a further change has been introduced, wherein the default y-offset has been artificially set to be 0.0 arcmin. To accomplish this, the source position was artificially fixed to be in a position of chipx=210 chipy=520 (SIM_Z offset=0.0, yoffset=0.0). As a result of the shift of the grating pattern from a y-offset of 1.5 arcmin for Cycle 18 to y-offset=0.0 arcmin in Cycle 19, the chip edges appear to be moved between the Cycle 18 and CY18 plots. However, the major differences between the last cycle and this cycle for LETG/ACIS-S is the new CONTAM N0010 being introduced in Cycle 19. See CalDB input file updates listed below.

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 4.9 routines mkarf for imaging aimpoint cases and mkgarf for gratings configurations, using the most current CALDB input files (CALDB 4.7.3). 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 18 (N0018) and Cycle 19 (N0019) 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 19:

CalDB Input File Uprades (since Cycle 18):

  1. ACIS CONTAM version N0010 replaces N0009: This produces considerable changes in all of the ACIS effective areas at or near the Carbon K-edge (~284-4000 eV). ACIS OBF contamination continues to increase, and the rate and composition of the contaminant are both temporally and spatially variable. The new CONTAM version N0010 file in CalDB 4.7.3 actually improves the modeling of most recent observations. However, the predictive affect of the new model for mid-2018 is quite striking at the lowest ACIS energies. This results in a reduction of the effective areas below the Oxygen K-edge in all of the ACIS-related PIMMS configurations.

  2. HRC-S QEU change to the 2018 file: This results in a -0.9% change in the HRC-S-related configurations for Cycle 19 relative to Cycle 18. See the HRC-S Aimpoint Difference plot below for a clear illustration of the changes to the HRC-S QEU, and hence the effective area. (The other inputs to the HRC-S-related EA's have not changed.)

Parameter Input Changes (versus CY18 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 19 the value is 642729669.184, which corresponds to UTC date 15 May 2018. For Cycle 18 the value was 611193668.184, corresponding to 15 May 2017. This affects all and only ACIS configurations. For ACIS-S aimpoint position EAs and grating zeroth order EAs, the change is at most -6% at the Carbon Edge, and significantly less elsewhere.


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 acisD1999-08-13contamN0009.fits
acisD1999-08-13contamN0010.fits
611193668.184
642729669.184
N/A N/A acisiD2015-11-17pimmsN0018.fits
acisiD2016-11-22pimmsN0019.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 acisD1999-08-13contamN0009.fits
acisD1999-08-13contamN0010.fits
611193668.184
642729669.184
N/A N/A acissD2015-11-17pimmsN0018.fits
acissD2016-11-22pimmsN0019.fits
HRC-I (7590.0, 7745.0) 8531 hrmaD1996-12-20axeffaN0008.fits hrciD1999-07-22qeN0009.fits hrciD1999-07-22qeuN0002.fits N/A N/A N/A N/A N/A hrciD2015-11-17pimmsN0018.fits
hrciD2016-11-22pimmsN0019.fits
HRC-S (2095.0, 8915.0) 9630 hrmaD1996-12-20axeffaN0008.fits hrcsD2012-03-29qeN0014.fits hrcsD2017-01-01qeuN0007.fits
hrcsD2018-01-01qeuN0007.fits
N/A N/A N/A N/A N/A hrcsD2015-12-02pimmsN0018.fits
hrcsD2016-11-22pimmsN0019.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 acisD1999-08-13contamN0009.fits
acisD1999-08-13contamN0010.fits
611193668.184
642729669.184
N/A hetgD1996-11-01greffpr001N0007.fits acisihetg0D2015-11-17pimmsN0018.fits
acisihetg0D2016-11-22pimmsN0019.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 acisD1999-08-13contamN0009.fits
acisD1999-08-13contamN0010.fits
611193668.184
642729669.184
N/A hetgD1996-11-01greffpr001N0007.fits acisshetg0D2015-11-17pimmsN0018.fits
acisshetg0D2016-11-22pimmsN0019.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 acisD1999-08-13contamN0009.fits
acisD1999-08-13contamN0010.fits
611193668.184
642729669.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0007.fits acissheg1D2015-11-17pimmsN0018.fits
acissheg1D2016-11-22pimmsN0019.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 acisD1999-08-13contamN0009.fits
acisD1999-08-13contamN0010.fits
611193668.184
642729669.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0007.fits acisshegmeg1D2015-11-17pimmsN0018.fits
acisshegmeg1D2016-11-22pimmsN0019.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 acisD1999-08-13contamN0009.fits
acisD1999-08-13contamN0010.fits
611193668.184
642729669.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0007.fits acissmeg1D2015-11-17pimmsN0018.fits
acissmeg1D2016-11-22pimmsN0019.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 acisD1999-08-13contamN0009.fits
acisD1999-08-13contamN0010.fits
611193668.184
642729669.184
acisD2000-01-29osip_ctiN0006.fits letgD1996-11-01greffpr001N0007.fits acisiletg0D2015-11-17pimmsN0018.fits
acisiletg0D2016-11-22pimmsN0019.fits
LETG0/ACIS-S (21.8, 512.0)
(210.0 520.0)
10662 hrmaD1996-12-20axeffaN0008.fits acisD1997-04-17qeN0006.fits acisD2010-02-01qeuN0007.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0009.fits
acisD1999-08-13contamN0010.fits
611193668.184
642729669.184
acisD2000-01-29osip_ctiN0006.fits letgD1996-11-01greffpr001N0007.fits acissletg0D2015-11-17pimmsN0018.fits
acissletg0D2016-11-23pimmsN0019.fits
LEG1/ACIS-S (21.8, 512.0)
(210.0 520.0)
10662 hrmaD1996-12-20axeffaN0008.fits acisD1997-04-17qeN0006.fits acisD2010-02-01qeuN0007.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0009.fits
acisD1999-08-13contamN0010.fits
611193668.184
642729669.184
acisD2000-01-29osip_ctiN0006.fits letgD1996-11-01greffpr001N0007.fits acissleg1D2015-11-17pimmsN0018.fits
acissleg1D2016-11-23pimmsN0019.fits
LETG0/HRC-I (7590.0, 7745.0) 8531 hrmaD1996-12-20axeffaN0008.fits hrciD1999-07-22qeN0009.fits hrciD1999-07-22qeuN0002.fits N/A N/A N/A N/A letgD1996-11-01greffpr001N0007.fits hrciletg0D2015-11-17pimmsN0018.fits
hrciletg0D2016-11-22pimmsN0019.fits
LETG0/HRC-S (2116.9, 8850.3) 331 hrmaD1996-12-20axeffaN0008.fits hrcsD2012-03-29qeN0014.fits hrcsD2017-01-01qeuN0007.fits
hrcsD2018-01-01qeuN0007.fits
N/A N/A N/A N/A letgD1996-11-01greffpr001N0007.fits hrcsletg0D2015-12-02pimmsN0018.fits
hrcsletg0D2016-11-22pimmsN0019.fits
LEG1/HRC-S (2116.9, 8850.3) 331 hrmaD1996-12-20axeffaN0008.fits hrcsD2012-03-29qeN0014.fits hrcsD2017-01-01qeuN0006.fits
hrcsD2018-01-01qeuN0007.fits
N/A N/A N/A N/A letgD1996-11-01greffpr001N0007.fits hrcsleg1D2015-12-02pimmsN0018.fits
hrcsleg1D2016-11-22pimmsN0019.fits
LEGHI/HRC-S (2116.9, 8850.3) 331 hrmaD1996-12-20axeffaN0008.fits hrcsD2012-03-29qeN0014.fits hrcsD2017-01-01qeuN0006.fits
hrcsD2018-01-01qeuN0007.fits
N/A N/A N/A N/A letgD1996-11-01greffpr001N0007.fits hrcsleghiD2015-12-02pimmsN0018.fits
hrcsleghiD2016-11-22pimmsN0019.fits

Notes for Table 1:

None.

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Last modified: 9 December 2016
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