Resources
Response Matrices and Simulations
January 22, 2007: High precision XMS response matrix
This matrix is made for the SXT/SMS configuration, and is binned to 0.2 eV bins. For speed in doing simulations, the previous matrices (under November 20, 2006 below) should be used, but for high-precision work, these new matrices ensure that binning does not affect the results.
- conx-ea-101106-0p2.rsp
Note: Users of Xspec 12 will need to install patch 12.4.0g in order to load a matrix of this size. The patch is available for download here
November 20, 2006: Con-X Atlas-V Single Launch (ASL) Configuration
These response matricies are for the core SXT/XMS configuration without the SEP. They assume the mirrors with Ir coatings, a 4 SXT Configuration, 6um Bi absorber on the XMS and split inner/outer ring design for the SXT. They are based on calculations by P. B. Reid on 11-Oct-06. The 'b10' matrix is smaller and may be faster to use than the other, because the channels and binsizes have been increased 10x.
(Click on image for higher-resolution version)
February 11, 2005: We have updated the response matrices to reflect the detailed Flight Mirror Assembly (FMA) study carried out in November 2003. These matrices include all effects "end-to-end", including estimates for detector efficiencies, filtering, geometric obscurations, grating efficiency (assuming in-plane gratings), contamination losses, alignment, etc. The figure to the right shows the updated effective area curves for the RGS, the XMS, and the total area at R>300 where R=E/ΔE (half-energy width (HEW) for the RGS and full-width half-max (FWHM) for the XMS).
(Click on image for higher-resolution version)
The matrices assume a 4-telescope system for the baseline Constellation-X. We are considering two scenarios for Constellation-X, which have yet to be fully evaluated in a science trade study: one is the "In-Plane Gratings (IPG)" scenario with an IPG and the calorimeter and the other is the "Off-Plane Gratings (OPG)" scenario with an OPG and the calorimeter.
This first set of matrices (posted February 11, 2005) assume the In-Plane Gratings (IPG) scenario, corresponding to the resolution and effective area figures to the right. The effective area curves for the gratings have been updated since the FMA study of November 2003 to reflect an updated EDCCD design with an 100 Å aluminum optical blocking filter, and a grating with line density of 407 lines/mm. (Note: Efficiency from a grating having line density of 580 lines/mm was used in 2003, spectral resolution values have not changed.)
The effective area for the calorimeter assumes the filter transmission circa August 2004 (R. Kelley, GSFC) for a 2800 Å polyimide + 2100 Å aluminum + kevlar mesh filter. This thin filter is considered viable for the 10-m baseline Constellation-X configuration. For longer focal length configurations, the filter would likely not be as thin and thus would be much less transmissive at E < 1 keV. Note also that although the basic calorimeter specifications are the same for either the IPG or OPG scenario, the amount of the mirror that "sees" the calorimeter differs. Therefore, the calorimeter response is different based upon whether an OPG or IPG matrix is assumed.
For the response matrices, the calorimeter is assumed to have 2 eV spectral resolution (FWHM) at lower energies, degrading slightly to ~4-5 eV at higher energies. Note that calorimeters have a fixed ΔE (presented as FWHM) so the calorimeter curve reflects the current detector requirements for the calorimeter, not the actual performance of the calorimeter (e.g., the resolution curve might be built up with different types of calorimeter pixels in different locations of the array).
The spectral resolution values for the baseline Constellation-X mission with an in-plane grating are:
- 0.05 Å HEW, RGS, 1st order
- 0.025 Å HEW, RGS, 2nd order
- 0.0167 Å HEW, RGS, 3rd order
- 2-4 eV FWHM, XMS
We expect to post Off-Plane Gratings (OPG) response matrices at a later date. For details on potential OPG performance, please see Flanagan et al. 2004 and Cash, "The Off-Plane Option for the Reflection Grating Spectrometer", September 19, 2002 (a talk at the September 2002 FST meeting).
Simulated Constellation-X spectra using Webspec. Necessary exposure times can be calculated online via W3PIMMS.
Alternatively, you may download the response matrices below and perform the simulations on your own computer. The Constellation-X calorimeter response matrices have approximately 17000 spectral channels. XSPEC v10 is required to handle a matrix of this size.
Response Matrices Available
Naming Convention: The first three characters refer to the the IPG vs OPG scenario, the date is for the ray trace analysis done by Paul Reid (SAO), and the last several characters describe instrument for which the matrix was made.
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ipg_020105_xms.rsp
(8.8 Mb) |
Response matrix for the 2 eV (FWHM) calorimeter. The outer 89 shells of the mirror are covered by gratings and the other 127 shells are intercepted by the calorimeter. Note that the effective area for the calorimeter assumes the filter transmission circa August 2004 (R. Kelley, GSFC) for a 2800 Å polyimide + 2100 Å aluminum + kevlar mesh filter. This thin filter is considered viable for the 10-m baseline Constellation-X configuration. For longer focal length configurations, the filter would likely not be as thin and thus would be much less transmissive at E < 1 keV. |
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ipg_020105_rgs1.rsp
(0.8 Mb) |
Response for the -1 order of the baseline In-Plane Grating (IPG) described above. |
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ipg_020105_rgs1.rsp
(1.5 Mb) |
As above, but for -2 order. |
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ipg_020105_rgs1.rsp
(2.8 Mb) |
As above, but for -3 order. |
