Last modified: December 2022

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/ccm.html
AHELP for CIAO 4.15 Sherpa

ccm

Context: models

Synopsis

Galactic extinction: the Cardelli, Clayton, and Mathis model.

Syntax

ccm

Description

The interstellar extinction is calculated using the formula from [1] . This model is intended to be used to modify another model (e.g. by multiplying the two together). It is for use when the independent axis is in Angstrom.


Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.ebv      thawed          0.5 -3.40282e+38  3.40282e+38           
   mdl.r        thawed          3.2 -3.40282e+38  3.40282e+38           

ATTRIBUTES

The attributes for this object are:

Attribute Definition
ebv E(B-V)
r R_v

Notes

When evaluated on a binned grid, the lower-edges of the bins are used for the calculation.

References


Bugs

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

See Also

models
fm, lmc, seaton, sm, smc, xgal