Synopsis
The XSPEC tapec model: APEC emission spectrum with separate continuum and line temperatures.
Syntax
xstapec The xstapec 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. The set_xsxset and get_xsxset functions are used to set and query the XSPEC XSET parameters, in particular the keywords "APECROOT", "APECTHERMAL", "APECVELOCITY", "APECNOLINES", and "APEC_TRACE_ABUND".
Example
>>> create_model_component("xstapec", "mdl")
>>> print(mdl)Create a component of the xstapec model and display its default parameters. The output is:
mdl Param Type Value Min Max Units ----- ---- ----- --- --- ----- mdl.kT thawed 1 0.008 64 keV mdl.kTi thawed 1 0.008 64 keV mdl.Abundanc thawed 1 0 5 mdl.Redshift thawed 0 -0.999 10 mdl.norm thawed 1 0 1e+24
ATTRIBUTES
The attributes for this object are:
| Attribute | Definition |
|---|---|
| kT | Continuum temperature, in keV. |
| kTi | Line temperature, in keV. |
| Abundanc | The metal abundance of the plasma, as defined by the set_xsabund function and the "APEC_TRACE_ABUND" xset keyword (which defaults to 1.0). |
| Redshift | The redshift of the plasma. |
| norm | The normalization of the model: see [1] for an explanation of the units. |
References
- [1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelTapec.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.