Last modified: December 2018

URL: http://cxc.harvard.edu/sherpa/ahelp/xsismabs.html
AHELP for CIAO 4.11 Sherpa v1

xsismabs

Context: models

Synopsis

The XSPEC ismabs model: A high resolution ISM absorption model with variable columns for individual ions.

Syntax

xsismabs

The xsismabs model is a multiplivative model component.

Description

The model is described at [1] .


Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.H        thawed          0.1            0       100000      10^22
   mdl.HeII     frozen            0            0       100000      10^16
   mdl.CI       thawed         33.1            0       100000      10^16
   mdl.CII      frozen            0            0       100000      10^16
   mdl.CIII     frozen            0            0       100000      10^16
   mdl.NI       thawed         8.32            0       100000      10^16
   mdl.NII      frozen            0            0       100000      10^16
   mdl.NIII     frozen            0            0       100000      10^16
   mdl.OI       thawed         67.6            0       100000      10^16
   mdl.OII      frozen            0            0       100000      10^16
   mdl.OIII     frozen            0            0       100000      10^16
   mdl.NeI      thawed           12            0       100000      10^16
   mdl.NeII     frozen            0            0       100000      10^16
   mdl.NeIII    frozen            0            0       100000      10^16
   mdl.MgI      thawed          3.8            0       100000      10^16
   mdl.MgII     frozen            0            0       100000      10^16
   mdl.MgIII    frozen            0            0       100000      10^16
   mdl.Si_I     thawed         3.35            0       100000      10^16
   mdl.Si_II    frozen            0            0       100000      10^16
   mdl.Si_III   frozen            0            0       100000      10^16
   mdl.S_I      thawed         2.14            0       100000      10^16
   mdl.S_II     frozen            0            0       100000      10^16
   mdl.S_III    frozen            0            0       100000      10^16
   mdl.ArI      thawed         0.25            0       100000      10^16
   mdl.ArII     frozen            0            0       100000      10^16
   mdl.ArIII    frozen            0            0       100000      10^16
   mdl.CaI      thawed         0.22            0       100000      10^16
   mdl.CaII     frozen            0            0       100000      10^16
   mdl.CaIII    frozen            0            0       100000      10^16
   mdl.Fe       thawed         3.16            0       100000      10^16
   mdl.redshift frozen            0            0           10           

ATTRIBUTES

The attributes for this object are:

H

The equivalent hydrogen column (in units of 10^22 atoms/cm^2).

HeII, CI, CII, CIII, NI, NII, NIII, OI, OII, OIII, NeI, NeII, NeIII, MgI, MgII, MgIII, Si_I, Si_II, Si_III, S_I, S_II, S_III, ArI, ArII, ArIII, CaI, CaII, CaIII, Fe

The column for the species (in units of 10^16 atoms/cm^2).

redshift

The redshift of the absorber.

Notes

As Sherpa parameter names are case insensitive the parameters for Silicon and Sulfur include an underscore character after the element name to avoid conflict: that is Si_I and S_I refer to the XSPEC SiI and SI parameters respectively.

References

XSPEC version

CIAO 4.11 comes with support for version 12.10.0e of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec;
print(xspec.get_xsversion())'
12.10.0e

Bugs

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