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Previous: Sample Sessions
Using Multi-component Models
- Example 1. 2-temperature plasma model
- Example 2. Partial covering absorber
- Example 3. A redshifted example
Example 1. 2-temperature plasma model
*** 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 > mo plasma 6.6 logt 1.0 3e19 plasma 7.2 logt 1.0 3e19 0.5 1.0 PIMMS > output apec2t 0.1 4.0 0.002 PIMMS > inst rosat pspc open PIMMS > from flux ergs 0.1-2.0 u PIMMS > go 3e-11 * For PLASMA (APEC) model with kT= 0.3431keV (logT= 6.60), Abund=1.0; NH = 3.000E+19 + PLASMA (APEC) model with kT= 1.3657keV (logT= 7.20), Abund=1.0; NH = 3.000E+19 ( 0.5000 times component 1 at 1.0000 keV) and an unabsorbed flux ( 0.100- 2.000keV) of 3.000E-11 ergs/cm/cm/s (Internal model normalization = 1.474E-02) * PIMMS predicts 3.987E+00 cps with ROSAT PSPC OPEN PIMMS> quit
This first example illustrates the use of two-temperature plasma model. The absorption columns (to be specified explicitly for each component) are the same in this example. The second component has a flux at 1 keV which is 50% of the first component. Note, however, this is a tricky proposition for the line-rich plasma. It is best to check this via the output command, which allows the users to check the actual model spectrum.
Example 2. Partial covering absorber
*** 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 > mo brems 15 3e23 brems 15 1e20 0.1 10 ga 6.5 0.1 250 PIMMS > output partial 0.1 10.0 0.005 PIMMS > inst xmm pn thin PIMMS > go 0.5 asca sis * For thermal Bremsstrahlung model with kT= 15.0000 keV; NH = 3.000E+23 + thermal Bremsstrahlung model with kT= 15.0000 keV; NH = 1.000E+20 ( 0.1000 times component 1 at 10.0000 keV) + Gaussian model with E= 6.5000 keV; sigma= 0.1000 keV; NH = 3.000E+23 (Eq.W=250.0000 eV) and 5.000E-01 cps in ASCA SIS %!% Integration over the entire chip (not just in the source region) assumed (Internal model normalization = 9.009E-03) * PIMMS predicts 6.462E+00 cps with XMM PN THIN for on-axis observation, PATTERN=0-4, before dead time correction and assuming a 5 arcmin extraction radius enclosing ~100% of the PSF (The count rate within a more reasonable point source extraction region of ~15 arcsec radius would be roughly ~70% of this value) WARNING: The pile-up estimate is approximate % Pile-up and dead-time corrected count rates in 4 energy bands using various allowed window options are: Window Pileup Dead Corrected Good Count Rates Option frac. Time 0.1-0.4 0.4-1.0 1.0-2.5 2.5-10.0 Total Full 7.883% 7.0% 0.5357 0.9250 1.0405 2.7705 5.5363 FullExtd >10% 7.0% 0.4295 0.7417 0.8343 2.2216 4.4394 ? Large 5.190% 9.0% 0.5395 0.9315 1.0479 2.7901 5.5756 Small 0.482% 29.0% 0.4418 0.7629 0.8582 2.2850 4.5662 % Timing and Burst options are now only available for pn with the thick filter % Any pile-up predictions over 10% are highly uncertain PIMMS> quitThis example shows how to set up a spectrum suffering from partial covering absorption. In addition, a Gaussian is added which has a different syntax: the three parameters are the line energy (keV), the physical width (keV), and the equivalent width (eV). Absorbing column is assumed to be the same as the first component (it can be specified explicitly, as the third parameter before the equivalent width).
Example 3. A redshifte example
*** 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 > mo pl 1.7 3e23 ga 6.4 0.2 150 plasma 1.2 1.0 0.0 1.0 2.5 z 0.01 8e19 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 1.217 keV (log T is 7.15) and selected abundance is 1.0 PIMMS > output agn_sb 0.1 10.0 0.01 PIMMS > inst chandra acis-s PIMMS > go 1e-11 * For power law model with photon index = 1.7000; NH = 3.000E+23 + Gaussian model with E= 6.4000 keV; sigma= 0.2000 keV; NH = 3.000E+23 (Eq.W=150.0000 eV) + PLASMA (APEC) model with kT= 1.2172keV (logT= 7.15), Abund=1.0; NH = 0.000E+00 ( 1.0000 times component 1 at 2.5000 keV) ...redshifted with z= 0.0100 and a Galactic Nh= 8.000E+19 and a flux ( 2.000- 10.000keV) of 1.000E-11 ergs/cm/cm/s (Internal model normalization = 5.883E-03) * PIMMS predicts 2.000E-01 cps with CHANDRA ACIS-S % Pileup estimate for ACIS: Pile-up is generally tolerable (10.0 %) at a frame-time of 1.324 s PIMMS > quitIn this example, the entire composite model is to be redshifted with z=0.01. Absorption specified with each component is taken to be intrinsic (i.e., also redshifted). Additionally, a Galactic (unredshifted) absorption is specified. For "unabsorbed" flux, both intrinsic and Galactic absorption will temporarily be set to 0.
- Example 1. 2-temperature plasma model
- Example 2. Partial covering absorber
- Example 3. A redshifted example
Next: Extended Sources
This file was last modified on Wednesday, 14-May-2025 11:55:19 EDT