=2pt PCARMF v2.1.2
Keith Jahoda
April 17, 1997.
This memo describes briefly PCARMF v2.1.2, which is intended to be distributed as part of ftools v3.7. I highlight differences from previous versions and provide examples of the performance of these matrices. I also provide information on how to get the tools to generate these matrices, and provide the raw matrices from which any combination can be created.
Changes from previous versions
There are several substantial improvements in this version of the matrix generator. These are
1) New energy to channel coefficients for all detectors, all layers, all epochs. The supported model is 3, which first translates energy of the photon into number of secondary electrons, and then allows a quadratic fit for channel number as a function of number of electrons. The x-axis (number of electrons) is renormalized to be energy for convenience for plotting inside xspec. The translation between photon energy and number of thermal electrons is non linear, and provides a natural way to account for the non linearities in the energy to channel relationship at the Xenon absorption edges. The details of this transformation will be described in greater length elsewhere.
2) The lower end of the energy scale has been fixed by requiring that the energy of the Cas-A Fe line be 6.59 keV (front layer), and by minimizing chi-squared on 2.5-50 keV fits to the Crab spectrum on the second and third layers. The second condition has the effect of pegging the energy scale at the Xenon L-edge at 4.78 keV. The results for the second and third layers can be seen in the results shown for the Crab spectrum where the counts observed below 5 keV are due to the small transmission window below the L edge.
3) Matrices for lld_code=63 (i.e. all layers) are now explicitly the sum of lld_code=3 + 12 + 48 (I.e. the sum of the matrices for the first, second, and third layers). Previously the total response was an approximation to this; adding the individual layer matrices automatically gets the weighting of the three layers correctly in an energy dependent way.
4) Propane matrices are now supported, nad are individually generated for each PCU to account for the different gains. The normalization of propane response to xenon response is unexpected (i.e. not 1). Users are advised to let the normalization of the propane layer float relative to other layers for the time being. An example is shown in the results section.
5) There are no defaults for the scale_hack parameter, although the code still exists. This allows an ad hoc correction to the effective areas, but the user must supply his own corrections. (This means that version 2.1.2 of pcarmf will not work with the version of pcarsp released in ftools 3.6.1. An alternate script which must be edited to fit individual observations is given at the end of this document.)
6) Non standard keywords having to do with response matrix parameters are now written out as history keywords (and survive through MARFRMF). This should make comparing different versions of the matrices earsier.
The rest of this memo gives some representative results from the Crab, Cas A, and discusses the propane layer efficiency.
Results from the Crab
The goal of this section is to provide representative comparisons of the matrices at different high voltage settings, in different layers within the same detector, between individual detectors, and across all detectors and layers.
Figure 1 compares the first layer of PCU 0 for Crab (nebula plus pulsar) data from the In Orbit Checkout period and the "epoch 3" high voltage setting (i.e. all data taken after April 14, 1996). The data have been fit to a single power law with the interstellar absorption fixed at .
Figure 1: In Orbit checkout and epoch 3 comparison
An xspec format summary of the fit is given below. Note that I have allowed an arbitrary overall normalization between the two data sets ( ). The best fit power law index and normalization are 2.17 and 12.2, both of which seem slightly high compared to literature values. However, the derived 2 - 10 keV flux is which is within two percent of the flux derived from the values adopted by Zombeck (index 2.05 and normalization 10.0) and Schattenberg and Canizares (index 2.1 and norm 10.9). The agreement is in fact too good, since I have not accounted for deadtime (known to be for the Crab. In this (and all subsequent cases) the ancilliary response files are generated assuming that the open area of each detector is . This is corrected only for the individual pointing offsets from the science axis.
XSPEC> sh all 12:21:02 15-Apr-97 Auto-saving is done after every command. Fit statistic in use is Chi-Squared Minimization technique is Lev-Marq Weighting method is standard Convergence criterion = 1.0000000000000D-02 Querying enabled Prefit-renorming enabled Solar abundance table is angr Information for file 1 belonging to plot group 1, data group 1 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p0lr1_hv5.pha Background file :bg_p0lr1_hv5.pha No current correction Response (RMF) file : p0_l1_e3.rsp Auxiliary (ARF) file : p0.arf XSPEC filter : NONE Noticed channels 5 to 89 File integration time 800.0 and effective area 1.000 File observed count rate 2071. +/- 1.6153 cts/s Model predicted rate : 2071. Information for file 2 belonging to plot group 2, data group 2 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p0lr1_hv7.pha Background file :bg_p0lr1_hv7.pha No current correction Response (RMF) file : p0_l1_e1.rsp Auxiliary (ARF) file : p0.arf XSPEC filter : NONE Noticed channels 7 to 105 File integration time 416.0 and effective area 1.000 File observed count rate 2210. +/- 2.3134 cts/s Model predicted rate : 2209. mo = constant[1]( ( powerlaw[2] )wabs[3] ) --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = constant[1]( ( powerlaw[2] )wabs[3] ) Model Fit Model Component Parameter Unit Value Data par par comp group 1 1 1 constant factor 1.000 frozen 1 2 2 2 powerlaw PhoIndex 2.174 +/- 0.1380E-02 1 3 3 2 powerlaw norm 12.18 +/- 0.3103E-01 1 4 4 3 wabs nH 10^22 0.3000 frozen 1 5 5 4 constant factor 1.029 +/- 0.1343E-02 2 6 2 5 powerlaw PhoIndex 2.174 = par 2 2 7 3 5 powerlaw norm 12.18 = par 3 2 8 4 6 wabs nH 10^22 0.3000 = par 4 2 --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 668.0139 using 184 PHA bins. Reduced chi-squared = 3.690685 XSPEC> flux Model flux 3.725 photons ( 2.3502E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 1 Model flux 3.833 photons ( 2.4184E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 2 XSPEC> log none
Figure 2 shows a similar fit but here the different data sets come from the three layers of PCU 0 during the third epoch. The power law index is constrained to be the same in each layer but the relative normalization remains a free parameter. (That a relative normalization is needed indicates that there is still room for improvement in the matrices for the inner layers; not shown is the fact that the current matrices give slightly different values for the power las index if the second or third layers are fit individually)
Figure 2: Comparison of the 3 layers in PCU 0, epoch 3
Logging to file: e3_l123.log XSPEC> sh all 12:24:43 15-Apr-97 Auto-saving is done after every command. Fit statistic in use is Chi-Squared Minimization technique is Lev-Marq Weighting method is standard Convergence criterion = 1.0000000000000D-02 Querying enabled Prefit-renorming enabled Solar abundance table is angr Information for file 1 belonging to plot group 1, data group 1 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p0lr1_hv5.pha Background file :bg_p0lr1_hv5.pha No current correction Response (RMF) file : p0_l1_e3.rsp Auxiliary (ARF) file : p0.arf XSPEC filter : NONE Noticed channels 5 to 89 File integration time 800.0 and effective area 1.000 File observed count rate 2071. +/- 1.6153 cts/s Model predicted rate : 2071. Information for file 2 belonging to plot group 2, data group 2 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p0lr2_hv5.pha Background file :bg_p0lr2_hv5.pha No current correction Response (RMF) file : p0_l2_e3.rsp Auxiliary (ARF) file : p0.arf XSPEC filter : NONE Noticed channels 4 to 88 File integration time 800.0 and effective area 1.000 File observed count rate 210.6 +/-0.52550 cts/s Model predicted rate : 210.0 Information for file 3 belonging to plot group 3, data group 3 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p0lr3_hv5.pha Background file :bg_p0lr3_hv5.pha No current correction Response (RMF) file : p0_l3_e3.rsp Auxiliary (ARF) file : p0.arf XSPEC filter : NONE Noticed channels 4 to 88 File integration time 800.0 and effective area 1.000 File observed count rate 93.54 +/-0.36019 cts/s Model predicted rate : 92.91 mo = constant[1]( ( powerlaw[2] )wabs[3] ) --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = constant[1]( ( powerlaw[2] )wabs[3] ) Model Fit Model Component Parameter Unit Value Data par par comp group 1 1 1 constant factor 1.000 frozen 1 2 2 2 powerlaw PhoIndex 2.178 +/- 0.1625E-02 1 3 3 2 powerlaw norm 12.26 +/- 0.3627E-01 1 4 4 3 wabs nH 10^22 0.3000 frozen 1 5 5 4 constant factor 1.022 +/- 0.2844E-02 2 6 2 5 powerlaw PhoIndex 2.178 = par 2 2 7 3 5 powerlaw norm 12.26 = par 3 2 8 4 6 wabs nH 10^22 0.3000 = par 4 2 9 6 7 constant factor 1.008 +/- 0.4204E-02 3 10 2 8 powerlaw PhoIndex 2.178 = par 2 3 11 3 8 powerlaw norm 12.26 = par 3 3 12 4 9 wabs nH 10^22 0.3000 = par 4 3 --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 1146.454 using 255 PHA bins. Reduced chi-squared = 4.567546 XSPEC> flux Model flux 3.732 photons ( 2.3528E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 1 Lower range 2.00 reset by matrix bound to 2.46 Model flux 2.900 photons ( 2.0802E-08 ergs)cm**-2 s**-1 ( 2.456- 10.000) DtSet : 2 Lower range 2.00 reset by matrix bound to 2.99 Model flux 2.151 photons ( 1.7446E-08 ergs)cm**-2 s**-1 ( 2.992- 10.000) DtSet : 3 XSPEC> log none
Figure 3 shows joint fits to the first layer of each of the five individual detectors. The relative normalization is within a few percent in all cases (the maximum deviation is ). The photon index for all 5 detectors is 2.18, which is very similar to the values obtained above for PCU 0 only.
Figure 3: Comparison of the first layer in 5 PCUs, epoch 3
Logging to file: e3_p01234.log XSPEC> sh all 12:31:43 15-Apr-97 Auto-saving is done after every command. Fit statistic in use is Chi-Squared Minimization technique is Lev-Marq Weighting method is standard Convergence criterion = 1.0000000000000D-02 Querying enabled Prefit-renorming enabled Solar abundance table is angr Information for file 1 belonging to plot group 1, data group 1 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p0lr1_hv5.pha Background file :bg_p0lr1_hv5.pha No current correction Response (RMF) file : p0_l1_e3.rsp Auxiliary (ARF) file : p0.arf XSPEC filter : NONE Noticed channels 5 to 89 File integration time 800.0 and effective area 1.000 File observed count rate 2071. +/- 1.6153 cts/s Model predicted rate : 2070. Information for file 2 belonging to plot group 2, data group 2 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p1lr1_hv5.pha Background file :bg_p1lr1_hv5.pha No current correction Response (RMF) file : p1_l1_e3.rsp Auxiliary (ARF) file : p1.arf XSPEC filter : NONE Noticed channels 5 to 91 File integration time 800.0 and effective area 1.000 File observed count rate 2087. +/- 1.6217 cts/s Model predicted rate : 2086. Information for file 3 belonging to plot group 3, data group 3 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p2lr1_hv5.pha Background file :bg_p2lr1_hv5.pha No current correction Response (RMF) file : p2_l1_e3.rsp Auxiliary (ARF) file : p2.arf XSPEC filter : NONE Noticed channels 5 to 89 File integration time 800.0 and effective area 1.000 File observed count rate 2082. +/- 1.6199 cts/s Model predicted rate : 2081. Information for file 4 belonging to plot group 4, data group 4 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p3lr1_hv5.pha Background file :bg_p3lr1_hv5.pha No current correction Response (RMF) file : p3_l1_e3.rsp Auxiliary (ARF) file : p3.arf XSPEC filter : NONE Noticed channels 5 to 92 File integration time 800.0 and effective area 1.000 File observed count rate 2085. +/- 1.6205 cts/s Model predicted rate : 2083. Information for file 5 belonging to plot group 5, data group 5 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p4lr1_hv5.pha Background file :bg_p4lr1_hv5.pha No current correction Response (RMF) file : p4_l1_e3.rsp Auxiliary (ARF) file : p4.arf XSPEC filter : NONE Noticed channels 4 to 86 File integration time 800.0 and effective area 1.000 File observed count rate 2049. +/- 1.6069 cts/s Model predicted rate : 2048. mo = constant[1]( ( powerlaw[2] )wabs[3] ) --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = constant[1]( ( powerlaw[2] )wabs[3] ) Model Fit Model Component Parameter Unit Value Data par par comp group 1 1 1 constant factor 1.007 +/- 45.20 1 2 2 2 powerlaw PhoIndex 2.185 +/- 0.7787E-03 1 3 3 2 powerlaw norm 12.31 +/- 552.7 1 4 4 3 wabs nH 10^22 0.3000 frozen 1 5 5 4 constant factor 1.036 +/- 46.47 2 6 2 5 powerlaw PhoIndex 2.185 = par 2 2 7 3 5 powerlaw norm 12.31 = par 3 2 8 4 6 wabs nH 10^22 0.3000 = par 4 2 9 6 7 constant factor 1.013 +/- 45.42 3 10 2 8 powerlaw PhoIndex 2.185 = par 2 3 11 3 8 powerlaw norm 12.31 = par 3 3 12 4 9 wabs nH 10^22 0.3000 = par 4 3 13 7 10 constant factor 0.9898 +/- 44.40 4 14 2 11 powerlaw PhoIndex 2.185 = par 2 4 15 3 11 powerlaw norm 12.31 = par 3 4 16 4 12 wabs nH 10^22 0.3000 = par 4 4 17 8 13 constant factor 1.028 +/- 46.11 5 18 2 14 powerlaw PhoIndex 2.185 = par 2 5 19 3 14 powerlaw norm 12.31 = par 3 5 20 4 15 wabs nH 10^22 0.3000 = par 4 5 --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 3808.307 using 428 PHA bins. Reduced chi-squared = 9.045860 XSPEC> flux 2 10 Model flux 3.744 photons ( 2.3572E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 1 Model flux 3.849 photons ( 2.4234E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 2 Model flux 3.763 photons ( 2.3690E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 3 Model flux 3.678 photons ( 2.3158E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 4 Model flux 3.819 photons ( 2.4046E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 5 XSPEC> data 1:1-3 p0lr1_hv5 p0lr2_hv5 p0lr3_hv5 2:4-6 p1lr1_hv5 p1lr2_hv5 p1lr3_hv ... The value, 9, of upper limit of file no. range is outside the allowed range (1,7):/ The value, 12, of upper limit of file no. range is outside the allowed range (1,10):
Figure 4 shows a fit to all 5 detectors and all 3 layers in each detector. Seven relative normalizations are allowed, one each for each PCU and one each for the seond and third layers relative to the first. The results are quite similar to those already shown. The largest deviation in the ratio of data/model occur for the second and third layers near 2 keV and near 5 keV. The efficiency of the second and third layers is very low here, down by three orders of magnitude from the peak response on layer 2 and more than four orders of magnitude on layer 3. The log file omits the information about the associated files. The relative normalizations are within a few percent and the power law index is 2.19.
Figure 4: Comparison of all layers, all PCUs, epoch 3
mo = constant[1]*constant[2]( ( powerlaw[3] )wabs[4] ) --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = constant[1]*constant[2]( ( powerlaw[3] )wabs[4] ) Model Fit Model Component Parameter Unit Value Data par par comp group 1 1 1 constant factor 1.000 frozen 1 2 2 2 constant factor 1.000 frozen 1 3 3 3 powerlaw PhoIndex 2.189 +/- 0.7210E-03 1 4 4 3 powerlaw norm 12.51 +/- 0.1830E-01 1 5 5 4 wabs nH 10^22 0.3000 frozen 1 6 1 5 constant factor 1.000 = par 1 2 7 6 6 constant factor 1.024 +/- 0.1283E-02 2 8 3 7 powerlaw PhoIndex 2.189 = par 3 2 9 4 7 powerlaw norm 12.51 = par 4 2 10 5 8 wabs nH 10^22 0.3000 = par 5 2 11 1 9 constant factor 1.000 = par 1 3 12 7 10 constant factor 1.012 +/- 0.1900E-02 3 13 3 11 powerlaw PhoIndex 2.189 = par 3 3 14 4 11 powerlaw norm 12.51 = par 4 3 15 5 12 wabs nH 10^22 0.3000 = par 5 3 16 8 13 constant factor 1.025 +/- 0.1057E-02 4 17 2 14 constant factor 1.000 = par 2 4 18 3 15 powerlaw PhoIndex 2.189 = par 3 4 19 4 15 powerlaw norm 12.51 = par 4 4 20 5 16 wabs nH 10^22 0.3000 = par 5 4 21 8 17 constant factor 1.025 = par 16 5 22 6 18 constant factor 1.024 = par 7 5 23 3 19 powerlaw PhoIndex 2.189 = par 3 5 24 4 19 powerlaw norm 12.51 = par 4 5 25 5 20 wabs nH 10^22 0.3000 = par 5 5 26 8 21 constant factor 1.025 = par 16 6 27 7 22 constant factor 1.012 = par 12 6 28 3 23 powerlaw PhoIndex 2.189 = par 3 6 29 4 23 powerlaw norm 12.51 = par 4 6 30 5 24 wabs nH 10^22 0.3000 = par 5 6 31 9 25 constant factor 1.004 +/- 0.1035E-02 7 32 2 26 constant factor 1.000 = par 2 7 33 3 27 powerlaw PhoIndex 2.189 = par 3 7 34 4 27 powerlaw norm 12.51 = par 4 7 35 5 28 wabs nH 10^22 0.3000 = par 5 7 36 9 29 constant factor 1.004 = par 31 8 37 6 30 constant factor 1.024 = par 7 8 38 3 31 powerlaw PhoIndex 2.189 = par 3 8 39 4 31 powerlaw norm 12.51 = par 4 8 40 5 32 wabs nH 10^22 0.3000 = par 5 8 41 9 33 constant factor 1.004 = par 31 9 42 7 34 constant factor 1.012 = par 12 9 43 3 35 powerlaw PhoIndex 2.189 = par 3 9 44 4 35 powerlaw norm 12.51 = par 4 9 45 5 36 wabs nH 10^22 0.3000 = par 5 9 46 10 37 constant factor 0.9854 +/- 0.1016E-02 10 47 2 38 constant factor 1.000 = par 2 10 48 3 39 powerlaw PhoIndex 2.189 = par 3 10 49 4 39 powerlaw norm 12.51 = par 4 10 50 5 40 wabs nH 10^22 0.3000 = par 5 10 51 10 41 constant factor 0.9854 = par 46 11 52 6 42 constant factor 1.024 = par 7 11 53 3 43 powerlaw PhoIndex 2.189 = par 3 11 54 4 43 powerlaw norm 12.51 = par 4 11 55 5 44 wabs nH 10^22 0.3000 = par 5 11 56 10 45 constant factor 0.9854 = par 46 12 57 7 46 constant factor 1.012 = par 12 12 58 3 47 powerlaw PhoIndex 2.189 = par 3 12 59 4 47 powerlaw norm 12.51 = par 4 12 60 5 48 wabs nH 10^22 0.3000 = par 5 12 61 11 49 constant factor 1.018 +/- 0.1055E-02 13 62 2 50 constant factor 1.000 = par 2 13 63 3 51 powerlaw PhoIndex 2.189 = par 3 13 64 4 51 powerlaw norm 12.51 = par 4 13 65 5 52 wabs nH 10^22 0.3000 = par 5 13 66 11 53 constant factor 1.018 = par 61 14 67 6 54 constant factor 1.024 = par 7 14 68 3 55 powerlaw PhoIndex 2.189 = par 3 14 69 4 55 powerlaw norm 12.51 = par 4 14 70 5 56 wabs nH 10^22 0.3000 = par 5 14 71 11 57 constant factor 1.018 = par 61 15 72 7 58 constant factor 1.012 = par 12 15 73 3 59 powerlaw PhoIndex 2.189 = par 3 15 74 4 59 powerlaw norm 12.51 = par 4 15 75 5 60 wabs nH 10^22 0.3000 = par 5 15 --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 7863.804 using 1284 PHA bins. Reduced chi-squared = 6.162856 XSPEC> flux 2 10 Model flux 3.755 photons ( 2.3617E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 1 Lower range 2.00 reset by matrix bound to 2.46 Model flux 2.917 photons ( 2.0893E-08 ergs)cm**-2 s**-1 ( 2.456- 10.000) DtSet : 2 Lower range 2.00 reset by matrix bound to 2.99 Model flux 2.164 photons ( 1.7533E-08 ergs)cm**-2 s**-1 ( 2.992- 10.000) DtSet : 3 Model flux 3.849 photons ( 2.4207E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 4 Lower range 2.00 reset by matrix bound to 2.52 Model flux 2.879 photons ( 2.0973E-08 ergs)cm**-2 s**-1 ( 2.523- 10.000) DtSet : 5 Lower range 2.00 reset by matrix bound to 2.99 Model flux 2.218 photons ( 1.7971E-08 ergs)cm**-2 s**-1 ( 2.992- 10.000) DtSet : 6 Model flux 3.769 photons ( 2.3709E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 7 Lower range 2.00 reset by matrix bound to 2.46 Model flux 2.929 photons ( 2.0974E-08 ergs)cm**-2 s**-1 ( 2.456- 10.000) DtSet : 8 Lower range 2.00 reset by matrix bound to 2.99 Model flux 2.173 photons ( 1.7601E-08 ergs)cm**-2 s**-1 ( 2.992- 10.000) DtSet : 9 Model flux 3.700 photons ( 2.3273E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 10 Lower range 2.00 reset by matrix bound to 2.50 Model flux 2.803 photons ( 2.0304E-08 ergs)cm**-2 s**-1 ( 2.501- 10.000) DtSet : 11 Lower range 2.00 reset by matrix bound to 3.01 Model flux 2.109 photons ( 1.7163E-08 ergs)cm**-2 s**-1 ( 3.014- 10.000) DtSet : 12 Model flux 3.821 photons ( 2.4033E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 13 Lower range 2.00 reset by matrix bound to 2.48 Model flux 2.931 photons ( 2.1113E-08 ergs)cm**-2 s**-1 ( 2.478- 10.000) DtSet : 14 Lower range 2.00 reset by matrix bound to 2.99 Model flux 2.202 photons ( 1.7842E-08 ergs)cm**-2 s**-1 ( 2.992- 10.000) DtSet : 15 XSPEC> log none
Finally, figure 5 shows a simultaneous fit to pcu 0, propane and layer 1. The relative normalization of the propane layer is 0.65, which suggests that there is room for substantial improvement here. Nonetheless, the propane layer matrices may be suitable ( caveat emptor) for tracking changes at the lowest energies. Including the propane layer in the fit has a modest effect on the best fit index which has moved dow to 2.17.
Figure 5: Comparison of the propane and layer1 in PCU 0, epoch 3
Logging to file: p0_l1pr.log XSPEC> sh all 11:13:46 16-Apr-97 Auto-saving is done after every command. Fit statistic in use is Chi-Squared Minimization technique is Lev-Marq Weighting method is standard Convergence criterion = 1.0000000000000D-02 Querying enabled Prefit-renorming enabled Solar abundance table is angr Information for file 1 belonging to plot group 1, data group 1 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p0lr1_hv5.pha Background file :bg_p0lr1_hv5.pha No current correction Response (RMF) file : p0_l1_e3.rsp Auxiliary (ARF) file : p0.arf XSPEC filter : NONE Noticed channels 5 to 89 File integration time 800.0 and effective area 1.000 File observed count rate 2071. +/- 1.6153 cts/s Model predicted rate : 2071. Information for file 2 belonging to plot group 2, data group 2 telescope = XTE , instrument = PCA , channel type = PHA Current data file: p0pr.pha No current background No current correction Response (RMF) file : p0_l4_e3.rsp Auxiliary (ARF) file : p0.arf XSPEC filter : NONE Noticed channels 3 to 18 File integration time 912.0 and effective area 1.000 File observed count rate 465.9 +/-0.71475 cts/s Model predicted rate : 464.2 mo = constant[1]( ( powerlaw[2] )wabs[3] ) --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = constant[1]( ( powerlaw[2] )wabs[3] ) Model Fit Model Component Parameter Unit Value Data par par comp group 1 1 1 constant factor 1.000 frozen 1 2 2 2 powerlaw PhoIndex 2.169 +/- 0.1669E-02 1 3 3 2 powerlaw norm 12.06 +/- 0.3667E-01 1 4 4 3 wabs nH 10^22 0.3000 frozen 1 5 5 4 constant factor 0.6583 +/- 0.1464E-02 2 6 2 5 powerlaw PhoIndex 2.169 = par 2 2 7 3 5 powerlaw norm 12.06 = par 3 2 8 4 6 wabs nH 10^22 0.3000 = par 4 2 --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 1981.125 using 101 PHA bins. Reduced chi-squared = 20.21557 XSPEC> flux 2 10 Model flux 3.716 photons ( 2.3467E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 1 Model flux 2.443 photons ( 1.5405E-08 ergs)cm**-2 s**-1 ( 2.000- 10.000) DtSet : 2 XSPEC> flux 1 5 Lower range 1.00 reset by matrix bound to 1.79 Model flux 3.407 photons ( 1.5584E-08 ergs)cm**-2 s**-1 ( 1.786- 5.000) DtSet : 1 Model flux 4.502 photons ( 1.5129E-08 ergs)cm**-2 s**-1 ( 1.000- 5.000) DtSet : 2 XSPEC> log none
Results from Cas-A
Figure 6 shows data from the first layer fit to a power law plus Fe line. The fit value of the line is 6.58 keV. The line has been fit simultaneously to all five detectors. There is less data for detectors 3 and 4 as these detectors were off for part of the interval which was accumulated. Note that the energy of the Cas A Fe line was one of the inputs to the energy scale of these matrices, so this result cannot be directly compared with other values. Remaining structure in the ratio plot is due to inaccuracies in the width of the energy response or the lack of a sufficiently detailed continuum model. The parameters of the fit are also summarized.
Figure 6: Fits to the Cas A Fe line, front layer of all 5 detectors.
Logging to file: casa.log XSPEC> sh all 10:14:32 17-Apr-97 Auto-saving is done after every command. Fit statistic in use is Chi-Squared Minimization technique is Lev-Marq Weighting method is standard Convergence criterion = 1.0000000000000D-02 Querying enabled Prefit-renorming enabled Solar abundance table is angr Information for file 1 belonging to plot group 1, data group 1 telescope = XTE , instrument = PCA , channel type = PHA Current data file: casa_p0lr1.pha No current background No current correction Response (RMF) file : p0lr1_hv5.rsp Auxiliary (ARF) file : none XSPEC filter : NONE Noticed channels 10 to 19 File integration time 4112. and effective area 1.000 File observed count rate 33.31 +/-9.00065E-02 cts/s Model predicted rate : 33.29 Information for file 2 belonging to plot group 2, data group 2 telescope = XTE , instrument = PCA , channel type = PHA Current data file: casa_p1lr1.pha No current background No current correction Response (RMF) file : p1lr1_hv5.rsp Auxiliary (ARF) file : none XSPEC filter : NONE Noticed channels 11 to 19 File integration time 4112. and effective area 1.000 File observed count rate 28.94 +/-8.38983E-02 cts/s Model predicted rate : 28.94 Information for file 3 belonging to plot group 3, data group 3 telescope = XTE , instrument = PCA , channel type = PHA Current data file: casa_p2lr1.pha No current background No current correction Response (RMF) file : p2lr1_hv5.rsp Auxiliary (ARF) file : none XSPEC filter : NONE Noticed channels 10 to 19 File integration time 4112. and effective area 1.000 File observed count rate 33.27 +/-8.99496E-02 cts/s Model predicted rate : 33.25 Information for file 4 belonging to plot group 4, data group 4 telescope = XTE , instrument = PCA , channel type = PHA Current data file: casa_p3lr1.pha No current background No current correction Response (RMF) file : p3lr1_hv5.rsp Auxiliary (ARF) file : none XSPEC filter : NONE Noticed channels 11 to 21 File integration time 4112. and effective area 1.000 File observed count rate 16.77 +/-6.38666E-02 cts/s Model predicted rate : 16.77 Information for file 5 belonging to plot group 5, data group 5 telescope = XTE , instrument = PCA , channel type = PHA Current data file: casa_p4lr1.pha No current background No current correction Response (RMF) file : p4lr1_hv5.rsp Auxiliary (ARF) file : none XSPEC filter : NONE Noticed channels 10 to 18 File integration time 4112. and effective area 1.000 File observed count rate 14.28 +/-5.89300E-02 cts/s Model predicted rate : 14.26 mo = constant[1]( powerlaw[2] + gaussian[3] ) --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = constant[1]( powerlaw[2] + gaussian[3] ) Model Fit Model Component Parameter Unit Value Data par par comp group 1 1 1 constant factor 1.000 frozen 1 2 2 2 powerlaw PhoIndex 2.758 +/- 0.1014E-01 1 3 3 2 powerlaw norm 1.094 +/- 0.1968E-01 1 4 4 3 gaussian LineE keV 6.582 +/- 0.3397E-02 1 5 5 3 gaussian Sigma keV 0. frozen 1 6 6 3 gaussian norm 4.1565E-03 +/- 0.4864E-04 1 7 7 4 constant factor 1.037 +/- 0.4120E-02 2 8 2 5 powerlaw PhoIndex 2.758 = par 2 2 9 3 5 powerlaw norm 1.094 = par 3 2 10 4 6 gaussian LineE keV 6.582 = par 4 2 11 5 6 gaussian Sigma keV 0. = par 5 2 12 6 6 gaussian norm 4.1565E-03 = par 6 2 13 8 7 constant factor 1.004 +/- 0.3839E-02 3 14 2 8 powerlaw PhoIndex 2.758 = par 2 3 15 3 8 powerlaw norm 1.094 = par 3 3 16 4 9 gaussian LineE keV 6.582 = par 4 3 17 5 9 gaussian Sigma keV 0. = par 5 3 18 6 9 gaussian norm 4.1565E-03 = par 6 3 19 9 10 constant factor 0.4927 +/- 0.2301E-02 4 20 2 11 powerlaw PhoIndex 2.758 = par 2 4 21 3 11 powerlaw norm 1.094 = par 3 4 22 4 12 gaussian LineE keV 6.582 = par 4 4 23 5 12 gaussian Sigma keV 0. = par 5 4 24 6 12 gaussian norm 4.1565E-03 = par 6 4 25 10 13 constant factor 0.4852 +/- 0.2398E-02 5 26 2 14 powerlaw PhoIndex 2.758 = par 2 5 27 3 14 powerlaw norm 1.094 = par 3 5 28 4 15 gaussian LineE keV 6.582 = par 4 5 29 5 15 gaussian Sigma keV 0. = par 5 5 30 6 15 gaussian norm 4.1565E-03 = par 6 5 --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 354.4485 using 49 PHA bins. Reduced chi-squared = 8.645085 XSPEC> eqw 3 Additive group equiv width for model 3 (gaussian): 688. eV Additive group equiv width for model 6 (gaussian): 688. eV Additive group equiv width for model 9 (gaussian): 688. eV Additive group equiv width for model 12 (gaussian): 688. eV Additive group equiv width for model 15 (gaussian): 688. eV XSPEC> log none
Propane efficiency
The propane layer is filled with proapne at an approximate pressure of 800 torr. Additionally it is known that during ground operations some xenon leaked out of the main volume into the propane volume. The amount of xenon in each propane volume is a parameter in the construction of the matrices. At the present we treat this value as a constant (i.e. there is no time dependance). The xenon does contribute appreciable opacity, particularly above the Xenon L edge, and therefore has an effect on the estimated efficiency in the main detector volume. Figure 7 shows the relative efficiency of the propane and 3 xenon layers for PCU 0. The value of the propane layer (beyond background rejection) is that it has the potential to extend the sensitive energy range to substantially lower values.
Figure 7: Relative efficiency of the propane and 3 xenon layers in
PCU 0.
Figure 8 shows the relative efficiency which is derived from the propane and the xenon oresent in the propane layer. Propane dominates the opacity below the xenon L edge, while xenon dominates the opacity above the L edge. The question of the relative efficiency of the propane layer relative to the first xenon layer requires further study.
Figure 8: Relative efficiency of the propane and xenon within the propane
layer of
PCU 0.