Last modified: December 2024

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/xscempow.html
AHELP for CIAO 4.17 Sherpa

xscempow

Context: models

Synopsis

The XSPEC cempow model: plasma emission, multi-temperature using a power-law emission measure.

Syntax

xscempow

The xscempow model is an additive model component.

Description

The model is described at [1] .


Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.alpha    frozen            1         0.01           20           
   mdl.Tmax     thawed            1      0.02725          100        keV
   mdl.nH       frozen            1        1e-06        1e+20      cm^-3
   mdl.abundanc 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
alpha The power-law index of the emissivity function.
Tmax The maximum temperature, in keV.
nH H density, in cm^-3.
abundanc The abundance relative to Solar, as set by set_xsabund .
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. See [1] for more details. This parameter can not be thawed.
norm The normalization of the model.

References

Changes in CIAO

Added in CIAO 4.17

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.

See Also

models
xsbcempow, xscemekl, xsvcempow