    The XSPEC c6pvmkl model: differential emission measure using Chebyshev representations with multi-temperature mekal.

xsc6pvmkl
The xsc6pvmkl model is an additive model component.

The model is described at [1] . It differs from xsc6vmekl by using the exponential of the 6th order Chebyshev polynomial.

>>> 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 1 -3.40282e+38 3.40282e+38 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. 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

XSPEC version

CIAO 4.16 comes with support for version 12.13.1e of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec; print(xspec.get_xsversion())'12.13.1e

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

December 2023