Synopsis
The XSPEC c6pvmkl model: differential emission measure using Chebyshev representations with multi-temperature mekal.
Syntax
xsc6pvmkl The xsc6pvmkl model is an additive model component.
Description
The model is described at [1] . It differs from xsc6vmekl by using the exponential of the 6th order Chebyshev polynomial.
Example
>>> create_model_component("xsc6pvmkl", "mdl")
>>> print(mdl)Create a component of the xsc6pvmkl model and display its default parameters. The output is:
mdl Param Type Value Min Max Units ----- ---- ----- --- --- ----- mdl.CPcoef1 thawed 1 -1 1 mdl.CPcoef2 thawed 0.5 -1 1 mdl.CPcoef3 thawed 0.5 -1 1 mdl.CPcoef4 thawed 0.5 -1 1 mdl.CPcoef5 thawed 0.5 -1 1 mdl.CPcoef6 thawed 0.5 -1 1 mdl.nH frozen 1 1e-06 1e+20 cm^-3 mdl.He frozen 1 0 10 mdl.C frozen 1 0 10 mdl.N frozen 1 0 10 mdl.O frozen 1 0 10 mdl.Ne frozen 1 0 10 mdl.Na frozen 1 0 10 mdl.Mg frozen 1 0 10 mdl.Al frozen 1 0 10 mdl.Si frozen 1 0 10 mdl.S frozen 1 0 10 mdl.Ar frozen 1 0 10 mdl.Ca frozen 1 0 10 mdl.Fe frozen 1 0 10 mdl.Ni frozen 1 0 10 mdl.Redshift frozen 0 -0.999 10 mdl.switch frozen 2 0 3 mdl.norm thawed 1 0 1e+24
ATTRIBUTES
The attributes for this object are:
| Attribute | Definition |
|---|---|
| CPcoef1, CPcoef2, CPcoef3, CPcoef4, CPcoef5, CPcoef6 | Chebyshev polynomial coefficients. |
| nH | H density, in cm^-3. |
| He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, Ni | The abundance relative to Solar. |
| Redshift | The redshift of the plasma. |
| switch | If 0, the mekal code is run to evaluate the model; if 1 then interpolation of the mekal data is used; if 2 then interpolation of APEC data is used; if 3 then SPEX data (only usable with XSPEC 12.14.0 or later). See [1] for more details. This parameter can not be thawed. |
| norm | The normalization of the model. |
References
- [1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelC6mekl.html
Changes in CIAO
Changed in CIAO 4.17
The switch parameter default has changed from 1 to 2 to match XSPEC 12.14.0 and the maximum value is now 3.
XSPEC version
CIAO 4.17 comes with support for version 12.14.0k of the XSPEC models. This can be checked with the following:
% python -c 'from sherpa.astro import xspec; print(xspec.get_xsversion())' 12.14.0k
Bugs
See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.