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Last modified: 27 November 2007

URL: http://cxc.harvard.edu/caldb/prop_plan/pimms/pimms.html
Hardcopy (PDF): A4 | Letter

Cycle 10 PIMMS Effective Area Public Information

Return to: PIMMS Index


PIMMS effective area (EA) files are built using model observations (OBSIDs) with standard/default detector and SIM_Z configurations with the CIAO 3.4 routines mkarf for imaging aimpoint cases and mkgarf for gratings configurations, using the most current CALDB input files (CALDB 3.4.1). 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 CY09 (N0009) and CY10 (N0010) review 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.

General PIMMS Changes for Cycle 10: There have been several mostly minor updates for PIMMS effective areas (EA's) between CY09 and CY10. They are in one of five areas:

  1. Imaging aimpoints: The slow optical axis drift (with respect to the Science Instrument Module (SIM) has continued with the progress of the mission. Hence the default position for an imaging observation strikes each detector in a slightly different place. We include default Y- and Z- offsets to optimize the chipx and chipy positions for ACIS-I and ACIS-S. The change in position presents a slightly different QE and mirror vignetting in the CIAO modeling that is done to calculate PIMMS EA's.

  2. ACIS FI chip Dead Area correction: This is a 2.5-4% reduction in the available area of the detector due to cosmic rays. The effect is tiny and uncalibrated for the BI chips, so no correction is included for them.

  3. ACIS CONTAM time-delay shift: For each cycle the future OBF contamination level is projected for the mid-point of the anticipated observation period. For CY10 the time and date are set for 15 May 2009, whereas for CY09 it was set for 15 May 2008. This produces at most a 1.5% decrease in the aimpoint effective area, mainly near the Carbon K-edge, from CY09 to CY10.

  4. The HETG/ACIS-S model obsid has changed from 2527 to 7280, which results in a significant shift in the location of the chip gaps and the S1 chip in energy space, and the source position for the zeroth order QE. This results in the apparently large oscillating differences between the HEG 1st and MEG 1st order areas. ObsID 7280 is more representative of the default source location for HETG/ACIS-S, and we have made this switch now to keep pace with the evolution of the defaults, despite the sudden changes between CY09 and CY10 here.

  5. HRC-S QE near the Oxygen K-edge: The HRC-S QE upgrade from version N0008 to N0009 was approved and installed in CalDB 3.3.0 in January 2007. So, version N0009 must now be used in the CY10 PIMMS calculations. The effect is very narrow near the Oxygen K-edge, and produces a 10% narrow spike in the EA curve at that point for HRC-S.

Summary of PIMMS changes for ACIS:

Beginning with Cycle 05, a correction for the time-dependent contaminant absorption has been included in all ACIS-related PIMMS effective areas. Cycle 10 PIMMS EA's have been projected for 15 May 2009 using the most recent model for the time dependence of the ACIS QE (aka CONTAM), which includes the spatial dependence of the contaminating layer on the ACIS OBF. The date projection was done using the detsubsys parameter option "TIME=358732865.184s" in either of the CIAO routines mkarf or mkgarf. The CY09 PIMMS EA's were projected for 15 May 2008 using the same CONTAM routine as in CY10 and with the delay parameter "TIME=327196864.184s". The predicted increase in Carbon K-edge absorption is very subtle using our current model between CY10 and CY09, and the QEU upgrades for the ACIS-S chips easily swamps this affect in terms of count rate calculations over broad energy ranges.

Summary of changes for HRC-I: The only change here is to the aimpoints and the applicable energy range, which has been extended to include the 60-100 eV range at the lower end.

Summary of changes for HRC-S: There has been an upgrade to the HRC-S QE file from last cycle, and it includes more accurate detailing of the O K-edge. The aimpoint and the energy range have also been updated.

Summary of changes for HETG/ACIS-S Here, the model ObsID has been updated to 7280, which has a Y-offset and source position that is more representative of the defaults for this case. The net change in the effective area from last year, over the full energy range, is not significant; however, the newer observation has the chip gaps and the S1 position somewhat shifted, resulting some shifts on the difference plots for this configuration. We elect to deal with these changes now, rather than to delay the changes to another cycle. Some users may find the EAs over narrow energy bands are significantly different. Detailed modeling of any specific source is necessary to ensure that chip gaps are optimally placed by varying the Y-offset if necessary.

In addition, the CONTAM correction has been updated, as with the other ACIS configurations above, and the ACIS DEAD AREA corrections have been added for the FI chips in the array. These amount to only a few percent changes in the EA.

Summary of changes for LETG/ACIS-S Here, the model ObsID has NOT been updated, and so the source position and chip gaps are exactly the same as before. The CONTAM has been updated as with the ACIS configurations above, and the DEAD AREA correction, a less-than-4% effect, has been added to the FI chips only.

Summary of changes for LETG/HRC-I: The default aimpoint has been changed for HRC-I, just as it has been for the HRC-I imaging case above. This amounts to a trivial change in the QE only, due to the very slight position shift. The 60-100eV energy range has also been added at the lower end of the spectrum.

Summary of changes for LETG/HRC-S: The new HRC-S QE has been applied here, as with the HRC-S imaging configuration above, contributing a very narrow region in which a 10% spike occurs in the differences from the CY09 traces at the Oxygen K-edge. The model ObsID is still 331, and hence the source position is not changed, nor are the two HRC-S chip gaps shifted at all from last cycle.

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 (949, 978)
(972, 964)
2858 hrmaD1996-12-20axeffaN0007.fits acisD1997-04-17qeN0006.fits acisD2000-01-29qeuN0006.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0004.fits 327196864.184
358732865.184
N/A N/A acisiD2006-10-26pimmsN0009.fits
acisiD2007-11-04pimmsN0010.fits
ACIS-S (215, 497)
(224, 520)
2850
8510
hrmaD1996-12-20axeffaN0007.fits acisD1997-04-17qeN0006.fits acisD2000-01-29qeuN0006.fits N/A acisD1999-08-13contamN0004.fits 327196864.184
358732865.184
N/A N/A acissD2006-10-26pimmsN0009.fits
acissD2007-11-04pimmsN0010.fits
HRC-I (7638.84, 7796.56)
(7630.41, 7845.24)
2608 hrmaD1996-12-20axeffaN0007.fits hrciD1999-07-22qeN0007.fits hrciD1999-07-22qeuN0002.fits N/A N/A N/A N/A N/A hrciD2006-10-26pimmsN0009.fits
hrciD2007-11-04pimmsN0010.fits
HRC-S (2287.42, 8935.69)
(2092.44, 8948.17)
 
2650
hrmaD1996-12-20axeffaN0007.fits hrcsD1999-07-22qeN0008.fits hrcsD1999-07-22qeN0009.fits hrcsD1999-07-22qeuN0004.fits N/A N/A N/A N/A N/A hrcsD2006-10-26pimmsN0009.fits
hrcsD2007-11-04pimmsN0010.fits
HETG0/ACIS-I (949, 978)
(972, 964)
2858 hrmaD1996-12-20axeffaN0007.fits acisD1997-04-17qeN0005.fits
acisD2000-01-29qeN0006.fits
acisD2000-01-29qeuN0006.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0004.fits 327196864.184
358732865.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0005.fits acisihetg0D2006-10-26pimmsN0009.fits
acisihetg0D2007-11-04pimmsN0010.fits
HETG0/ACIS-S (290, 393)
(231, 393)
2527
7280
hrmaD1996-12-20axeffaN0007.fits acisD2000-01-29qeN0006.fits acisD2000-01-29qeuN0006.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0004.fits 327196864.184
358732865.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0005.fits acisshetg0D2006-10-26pimmsN0009.fits
acisshetg0D2007-11-04pimmsN0010.fits
HEG1/ACIS-S (290, 393)
(231, 393)
2527
7280
hrmaD1996-12-20axeffaN0007.fits acisD2000-01-29qeN0006.fits acisD2000-01-29qeuN0006.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0004.fits 327196864.184
358732865.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0005.fits acissheg1D2006-10-26pimmsN0009.fits
acissheg1D2007-11-04pimmsN0010.fits
HEGMEG1/ACIS-S (290, 393)
(231, 393)
2527
7280
hrmaD1996-12-20axeffaN0007.fits acisD2000-01-29qeN0006.fits acisD2000-01-29qeuN0006.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0004.fits 327196864.184
358732865.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0005.fits acisshegmeg1D2006-10-26pimmsN0009.fits
acisshegmeg1D2007-11-04pimmsN0010.fits
MEG1/ACIS-S (290, 393)
(231, 393)
2527
7280
hrmaD1996-12-20axeffaN0007.fits acisD2000-01-29qeN0006.fits acisD2000-01-29qeuN0006.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0004.fits 327196864.184
358732865.184
acisD2000-01-29osip_ctiN0006.fits hetgD1996-11-01greffpr001N0005.fits acissmeg1D2006-10-26pimmsN0009.fits
acissmeg1D2007-11-04pimmsN0010.fits
LETG0/ACIS-S (293, 190) 2297 hrmaD1996-12-20axeffaN0007.fits acisD2000-01-29qeN0006.fits acisD2000-01-29qeuN0006.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0004.fits 327196864.184
358732865.184
acisD2000-01-29osip_ctiN0006.fits letgD1996-11-01greffpr001N0005.fits acissletg0D2006-10-26pimmsN0009.fits
acissletg0D2007-11-04pimmsN0010.fits
LEG1/ACIS-S (293, 190) 2297 hrmaD1996-12-20axeffaN0007.fits acisD2000-01-29qeN0006.fits acisD2000-01-29qeuN0006.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0004.fits 327196864.184
358732865.184
acisD2000-01-29osip_ctiN0006.fits letgD1996-11-01greffpr001N0005.fits acissleg1D2006-10-26pimmsN0009.fits
acissleg1D2007-11-04pimmsN0010.fits
LETG0/ACIS-I (949, 978)
(972, 964)
2858 hrmaD1996-12-20axeffaN0007.fits acisD2000-01-29qeN0006.fits acisD2000-01-29qeuN0006.fits acisD1999-09-16dead_areaN0001.fits acisD1999-08-13contamN0004.fits 327196864.184
358732865.184
acisD2000-01-29osip_ctiN0006.fits letgD1996-11-01greffpr001N0005.fits acisiletg0D2006-10-26pimmsN0009.fits
acisiletg0D2007-11-04pimmsN0010.fits
LETG0/HRC-I (7638.84, 7796.56)
(7630.41, 7845.24)
2608 hrmaD1996-12-20axeffaN0007.fits hrciD1999-07-22qeN0007.fits hrciD1999-07-22qeuN0002.fits N/A N/A N/A N/A letgD1996-11-01greffpr001N0005.fits hrciletg0D2006-10-26pimmsN0009.fits
hrciletg0D2007-11-04pimmsN0010.fits
LETG0/HRC-S  (2201, 8977) 331 hrmaD1996-12-20axeffaN0007.fits hrcsD1999-07-22qeN0008.fits
hrcsD1999-07-22qeN0009.fits
hrcsD1999-07-22qeuN0004.fits N/A N/A N/A N/A letgD1996-11-01greffpr001N0005.fits hrcsletg0D2006-10-26pimmsN0009.fits
hrcsletg0D2007-11-04pimmsN0010.fits
LEG1/HRC-S  (2201, 8977) 331 hrmaD1996-12-20axeffaN0007.fits hrcsD1999-07-22qeN0008.fits
hrcsD1999-07-22qeN0009.fits
hrcsD1999-07-22qeuN0004.fits N/A N/A N/A N/A letgD1996-11-01greffpr001N0005.fits hrcsleg1D2006-10-26pimmsN0009.fits
hrcsleg1D2007-11-04pimmsN0010.fits
LEGHI/HRC-S  (2201, 8977) 331 hrmaD1996-12-20axeffaN0007.fits hrcsD1999-07-22qeN0008.fits
hrcsD1999-07-22qeN0009.fits
hrcsD1999-07-22qeuN0004.fits N/A N/A N/A N/A letgD1996-11-01greffpr001N0005.fits hrcsleghiD2006-10-26pimmsN0009.fits
hrcsleghiD2007-11-04pimmsN0010.fits

Notes for Table 1:

None.

Return to: PIMMS Index

Hardcopy (PDF): A4 | Letter
Last modified: 27 November 2007


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