Last modified: December 2023

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/xscplinear.html
AHELP for CIAO 4.16 Sherpa

xscplinear

Context: models

Synopsis

The XSPEC cplinear model: a non-physical piecewise-linear model for low count background spectra.

Syntax

xscplinear

The xscplinear model is an additive model component.

Description

The model is described at [1] .


Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.energy00 frozen          0.5            0           10        keV
   mdl.energy01 frozen            1            0           10        keV
   mdl.energy02 frozen          1.5            0           10        keV
   mdl.energy03 frozen            2            0           10        keV
   mdl.energy04 frozen            3            0           10        keV
   mdl.energy05 frozen            4            0           10        keV
   mdl.energy06 frozen            5            0           10        keV
   mdl.energy07 frozen            6            0           10        keV
   mdl.energy08 frozen            7            0           10        keV
   mdl.energy09 frozen            8            0           10        keV
   mdl.log_rate00 frozen            0          -20           20           
   mdl.log_rate01 frozen            1          -20           20           
   mdl.log_rate02 frozen            0          -20           20           
   mdl.log_rate03 frozen            1          -20           20           
   mdl.log_rate04 frozen            0          -20           20           
   mdl.log_rate05 frozen            1          -20           20           
   mdl.log_rate06 frozen            0          -20           20           
   mdl.log_rate07 frozen            1          -20           20           
   mdl.log_rate08 frozen            0          -20           20           
   mdl.log_rate09 frozen            1          -20           20           
   mdl.norm     thawed            1            0        1e+24           

ATTRIBUTES

The attributes for this object are:

Attribute Definition
energy00, energy01, energy02, energy03, energy04, energy05, energy06, energy07, energy08, energy09 Energy in keV.
log_rate01, log_rate02, log_rate03, log_rate04, log_rate05, log_rate06, log_rate07, log_rate08, log_rate09 Log of the rate.
norm The normalization of the model.

References

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.