HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.

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Previous: Introduction

Sample Sessions

In this section, examples using PIMMS version 4.0 are shown to illustrate the general feel of PIMMS sessions.

Example 1. Estimating Chandra ACIS-I count rates

*** PIMMS version 4.11 ***
    2020 Feb 27th Release
    Reading mission directory, please wait
* Current model is BREMSSTRAHLUNG, kT=  10.0000 keV; NH =  1.000E+21
   <--- Use 'MODEL' command to change
        and 'PLASMA' command to switch among APEC/mekal/RS
* By default, input rate is taken to be
 Flux (      2.000-     10.000 keV) in ergs/cm/cm/s
   <--- Use 'FROM' command to change the default
* Simulation product will be
 Count rate in CHANDRA ACIS-I
   <--- Use 'INSTRUMENT' command to switch to another instrument
PIMMS > go 1 einstein ipc
* For thermal Bremsstrahlung model with kT= 10.0000 keV; NH =  1.000E+21
  and  1.000E+00 cps in EINSTEIN IPC
  (Internal model normalization =  5.602E-03)
* PIMMS predicts  2.977E+00 cps with CHANDRA ACIS-I
% Pileup estimate for ACIS:
  Pile-up is too high (21.4 %) at the fastest single-chip frame time (0.2 s)
  Consult the Chandra POG for mitigation methods
PIMMS > quit

In this example, the default spectral model is used to estimate the Chandra ACIS-I count rate (which happens to be the default). The only place where user did not use the default set-up was to specify conversion from Einstein IPC count rate. PIMMS not only reports the total ACIS-I count rate but also the pile-up fraction for such a source.

Example 2. Estimating XTE count rates I

*** PIMMS version 4.11 ***
    2020 Feb 27th Release
    Reading mission directory, please wait
* Current model is BREMSSTRAHLUNG, kT=  10.0000 keV; NH =  1.000E+21
   <--- Use 'MODEL' command to change
        and 'PLASMA' command to switch among APEC/mekal/RS
* By default, input rate is taken to be
 Flux (      2.000-     10.000 keV) in ergs/cm/cm/s
   <--- Use 'FROM' command to change the default
* Simulation product will be
 Count rate in CHANDRA ACIS-I
   <--- Use 'INSTRUMENT' command to switch to another instrument
PIMMS > from exosat me
PIMMS > inst xte pca
PIMMS > mo plasma 1 1.0 5e19
NOTE: This version of PIMMS has a grid of  59x 5 grid of APEC models
      from kT= 0.034 keV (logT= 5.60) to kT=27.250 keV (logT= 8.50)
      and abundances from 0.20 to 1.00
         Selected temperature is  0.967 keV (log T is  7.05)
         and selected abundance is 1.0
PIMMS > go 1
* For PLASMA (APEC) model with
                        kT= 0.9669keV (logT= 7.05), Abund=1.0; NH =  5.000E+19
  and  1.000E+00 cps in EXOSAT ME
  (Internal model normalization =  3.655E-02)
* PIMMS predicts  2.441E-01 cps with XTE PCA
   (Count rate is per PCU)

%%%        With 3 PCUs operational:
           (Use these numbers in RPS)

PIMMS predicts     0.732 cps from the source plus    91.380 background cps
5-sigma detection will be achieved in 4295.926s
(but undetectable with 1% systematic uncertainties in bgd)

Results in the 6 canonical XTE PCA bands are:

Channels  Nominal    Source   BGD   5-sigma    (+1%)
          E (keV)    (cps)    (cps) detection (s)
  0- 13  0.00- 6.14     0.695 10.56  582.266 ( 1376.175)
 14- 17  6.14- 7.90     0.031  3.46 9.00E+04 (*********)
 18- 23  7.90- 10.5  5.47E-03  4.56 3.82E+06 (*********)
 24- 35  10.5- 15.8  3.74E-04  7.87 1.41E+09 (*********)
 36- 49  15.8- 22.1  1.71E-06  8.90 7.62E+13 (*********)
 50-249  22.1-116.0  3.00E-09 56.05 1.56E+20 (*********)

%%% ...and with 2 PCUs operational:

PIMMS predicts     0.488 cps from the source plus    60.920 background cps
5-sigma detection will be achieved in 6.44E+03s
(but undetectable with 1% systematic uncertainties in bgd)

Results in the 6 canonical XTE PCA bands are:

Channels  Nominal    Source   BGD   5-sigma    (+1%)
          E (keV)    (cps)    (cps) detection (s)
  0- 13  0.00- 6.14     0.463  7.04  873.398 ( 2064.263)
 14- 17  6.14- 7.90     0.021  2.31 1.35E+05 (*********)
 18- 23  7.90- 10.5  3.64E-03  3.04 5.73E+06 (*********)
 24- 35  10.5- 15.8  2.49E-04  5.24 2.11E+09 (*********)
 36- 49  15.8- 22.1  1.14E-06  5.93 1.14E+14 (*********)
 50-249  22.1-116.0  2.00E-09 37.37 2.34E+20 (*********)
PIMMS > model plasma 1.0 1 1e20
NOTE: This version of PIMMS has a grid of  59x 5 grid of APEC models
      from kT= 0.034 keV (logT= 5.60) to kT=27.250 keV (logT= 8.50)
      and abundances from 0.20 to 1.00
         Selected temperature is  0.967 keV (log T is  7.05)
         and selected abundance is 1.0
PIMMS > plasma mekal
Current model has been changed
* Current model is PLASMA (mekal) with
                        kT= 0.9669keV (logT= 7.05), Abund=1.0; NH =  1.000E+20
PIMMS > go 1
* For PLASMA (mekal) model with
                        kT= 0.9669keV (logT= 7.05), Abund=1.0; NH =  1.000E+20
  and  1.000E+00 cps in EXOSAT ME
  (Internal model normalization =  3.307E-02)
* PIMMS predicts  2.528E-01 cps with XTE PCA
   (Count rate is per PCU)

%%%        With 3 PCUs operational:
           (Use these numbers in RPS)

PIMMS predicts     0.758 cps from the source plus    91.380 background cps
5-sigma detection will be achieved in 4005.449s
(but undetectable with 1% systematic uncertainties in bgd)

Results in the 6 canonical XTE PCA bands are:

Channels  Nominal    Source   BGD   5-sigma    (+1%)
          E (keV)    (cps)    (cps) detection (s)
  0- 13  0.00- 6.14     0.721 10.56  541.893 ( 1166.980)
 14- 17  6.14- 7.90     0.032  3.46 8.66E+04 (*********)
 18- 23  7.90- 10.5  4.87E-03  4.56 4.81E+06 (*********)
 24- 35  10.5- 15.8  2.76E-04  7.87 2.59E+09 (*********)
 36- 49  15.8- 22.1  8.02E-07  8.90 3.46E+14 (*********)
 50-249  22.1-116.0  7.71E-10 56.05 2.35E+21 (*********)

%%% ...and with 2 PCUs operational:

PIMMS predicts     0.506 cps from the source plus    60.920 background cps
5-sigma detection will be achieved in 6.01E+03s
(but undetectable with 1% systematic uncertainties in bgd)

Results in the 6 canonical XTE PCA bands are:

Channels  Nominal    Source   BGD   5-sigma    (+1%)
          E (keV)    (cps)    (cps) detection (s)
  0- 13  0.00- 6.14     0.481  7.04  812.840 ( 1750.471)
 14- 17  6.14- 7.90     0.021  2.31 1.30E+05 (*********)
 18- 23  7.90- 10.5  3.25E-03  3.04 7.22E+06 (*********)
 24- 35  10.5- 15.8  1.84E-04  5.24 3.89E+09 (*********)
 36- 49  15.8- 22.1  5.35E-07  5.93 5.19E+14 (*********)
 50-249  22.1-116.0  5.14E-10 37.37 3.53E+21 (*********)
PIMMS > quit
In this example, the user specified conversion from EXOSAT ME count rate to XTE PCA and used plasma models with two different absorbing columns, also switching from APEC (default) to mekal before the second run. Since PIMMS uses grids of pre-calculated plasma models, the temperature of the actual model used does not exactly match the request. PIMMS provides instrument-specific information for the XTE PCA (source and background count rates, and 5-sigma detection times in the entire passband and in the 6 canonical PCA bands with 2 or 3 PCUs operational).

Example 3. Estimating XTE count rates II

*** PIMMS version 4.11 ***
    2020 Feb 27th Release
    Reading mission directory, please wait
* Current model is BREMSSTRAHLUNG, kT=  10.0000 keV; NH =  1.000E+21
   <--- Use 'MODEL' command to change
        and 'PLASMA' command to switch among APEC/mekal/RS
* By default, input rate is taken to be
 Flux (      2.000-     10.000 keV) in ergs/cm/cm/s
   <--- Use 'FROM' command to change the default
* Simulation product will be
 Count rate in CHANDRA ACIS-I
   <--- Use 'INSTRUMENT' command to switch to another instrument
PIMMS > from ginga lac both
PIMMS > mo pl 1.5 15 30 1e22
PIMMS > inst xte pca
PIMMS > go 500
* For power-law model with high-energy cut-off with
  Index =  1.50, Ecut   15.00 keV, E(e-folding)   30.00 keV; NH =  1.000E+22
  and  5.000E+02 cps in GINGA LAC BOTH
  (Internal model normalization =  1.950E-01)
* PIMMS predicts  1.434E+02 cps with XTE PCA
   (Count rate is per PCU)

%%%        With 3 PCUs operational:
           (Use these numbers in RPS)

PIMMS predicts   430.284 cps from the source plus    91.380 background cps
5-sigma detection will be achieved in    0.070s
(or in    0.070s with 1% systematic uncertainties in bgd)

Results in the 6 canonical XTE PCA bands are:

Channels  Nominal    Source   BGD   5-sigma    (+1%)
          E (keV)    (cps)    (cps) detection (s)
  0- 13  0.00- 6.14   159.874 10.56    0.167 (    0.167)
 14- 17  6.14- 7.90    64.852  3.46    0.406 (    0.406)
 18- 23  7.90- 10.5    74.181  4.56    0.358 (    0.358)
 24- 35  10.5- 15.8    82.633  7.87    0.331 (    0.331)
 36- 49  15.8- 22.1    33.182  8.90    0.955 (    0.956)
 50-249  22.1-116.0    15.562 56.05    7.393 (    7.641)

%%% ...and with 2 PCUs operational:

PIMMS predicts   286.856 cps from the source plus    60.920 background cps
5-sigma detection will be achieved in    0.106s
(or in    0.106s with 1% systematic uncertainties in bgd)

Results in the 6 canonical XTE PCA bands are:

Channels  Nominal    Source   BGD   5-sigma    (+1%)
          E (keV)    (cps)    (cps) detection (s)
  0- 13  0.00- 6.14   106.582  7.04    0.250 (    0.250)
 14- 17  6.14- 7.90    43.235  2.31    0.609 (    0.609)
 18- 23  7.90- 10.5    49.454  3.04    0.537 (    0.537)
 24- 35  10.5- 15.8    55.089  5.24    0.497 (    0.497)
 36- 49  15.8- 22.1    22.121  5.93    1.433 (    1.433)
 50-249  22.1-116.0    10.375 37.37   11.089 (   11.461)
PIMMS > inst xte hexte def
PIMMS > go 500
* For power-law model with high-energy cut-off with
  Index =  1.50, Ecut   15.00 keV, E(e-folding)   30.00 keV; NH =  1.000E+22
  and  5.000E+02 cps in GINGA LAC BOTH
  (Internal model normalization =  1.950E-01)
* PIMMS predicts  1.789E+01 cps with XTE HEXTE DEFAULT
   (Source-only count rate in 1 cluster; BGD rate is 73.1 per cluster)
5-sigma detection will be achieved in     14.7s

Results in the 4 canonical XTE HEXTE bands are:
             (per HEXTE cluster)

  Channels Nominal   Source   BGD   5-sigma
           E (keV)   (cps)    (cps) detection (s)
    5- 29   12-  30    13.6   11.86      5.6
   30- 61   30-  62     3.6   17.93     86.4
   62-125   62- 126  6.56E-01 21.94   3004.3
  126-250  126- 250  1.35E-02 21.35 6.88E+06
 (The default 16-s rocking cycle is assumed for detection time)
PIMMS > quit
In this case, a special version of the power law model (with high energy cut-off) is used, by specifying index, cut-off energy and e-folding energy, as well as NH, on the command line. User then calculated PCA and HEXTE count rates for a 500 cps Ginga LAC source.

Example 4. Estimating ROSAT PSPC count rates

*** PIMMS version 4.11 ***
    2020 Feb 27th Release
    Reading mission directory, please wait
* Current model is BREMSSTRAHLUNG, kT=  10.0000 keV; NH =  1.000E+21
   <--- Use 'MODEL' command to change
        and 'PLASMA' command to switch among APEC/mekal/RS
* By default, input rate is taken to be
 Flux (      2.000-     10.000 keV) in ergs/cm/cm/s
   <--- Use 'FROM' command to change the default
* Simulation product will be
 Count rate in CHANDRA ACIS-I
   <--- Use 'INSTRUMENT' command to switch to another instrument
PIMMS > from flux ergs 0.1-4
PIMMS > mo plasma 6.65 logt 0.6 3e19
PIMMS > inst rosat pspc open
PIMMS > go 5e-12
* For PLASMA (APEC) model with
                        kT= 0.3849keV (logT= 6.65), Abund=0.6; NH =  3.000E+19
   and a flux (      0.100-      4.000keV) of  5.000E-12 ergs/cm/cm/s
  (Internal model normalization =  3.798E-03)
* PIMMS predicts  7.389E-01 cps with ROSAT PSPC OPEN
PIMMS > inst rosat pspc r6r7
PIMMS > go 5e-12
* For PLASMA (APEC) model with
                        kT= 0.3849keV (logT= 6.65), Abund=0.6; NH =  3.000E+19
   and a flux (      0.100-      4.000keV) of  5.000E-12 ergs/cm/cm/s
  (Internal model normalization =  3.798E-03)
* PIMMS predicts  1.207E-01 cps with ROSAT PSPC R6R7
PIMMS > quit
In this example, 0.6 Solar abundance, logT=6.65 APEC model with an absorption of 3x1019 cm-2 is used to estimate ROSAT PSPC count rates (total and a combination of the Snowden R bands) for a 5x10-12 ergs cm-2s-1 source.

Next: Using Multi-component Models

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HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.

This file was last modified on Wednesday, 26-Aug-2020 12:08:26 EDT