xsvgadem

Context: models

Synopsis

The XSPEC vgadem model: plasma emission, multi-temperature with gaussian distribution of emission measure.

Syntax

xsvgadem

The xsvgadem model is an additive model component.

Description

The model is described at [1] . The set_xsabund and get_xsabund functions change and return the current settings for the relative abundances of the metals. See the xsapec documentation for settings relevant to the APEC model (i.e. when switch=2 ).

Example

>>> create_model_component("xsvgadem", "mdl")
>>> print(mdl)

Create a component of the xsvgadem model and display its default parameters. The output is:

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.Tmean    frozen            4         0.01           20        keV
   mdl.Tsigma   thawed          0.1         0.01          100        keV
   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 -3.40282e+38  3.40282e+38           
   mdl.norm     thawed            1            0        1e+24

ATTRIBUTES

The attributes for this object are:

Attribute	Definition
Tmean	The mean temperature for the gaussian emission measure distribution, in keV.
Tsigma	The sigma of the temperature distribution for the gaussian emission measure, in keV.
nH	H density, in cm^-3.
He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, Ni	The abundance of the element in solar units.
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/XSmodelGadem.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

Bugs

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