xsbtapec

Context: models

Synopsis

The XSPEC btapec model: velocity broadened APEC emission spectrum with separate continuum and line temperatures.

Syntax

xsbtapec

The xsbtapec 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" and "APEC_TRACE_ABUND".

Example

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

Create a component of the xsbtapec 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 frozen            1            0            5           
   mdl.Redshift frozen            0       -0.999           10           
   mdl.Velocity frozen            0            0        10000       km/s
   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.
Velocity	The gaussian sigma of the velocity broadening, in km/s.
norm	The normalization of the model: see [1] for an explanation of the units.

References

[1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelBtapec.html

Changes in CIAO

Changed in CIAO 4.16

The maximum for the Velocity parameter has been changed from 10^6 to 10^4 km/s.

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.