Last modified: December 2023

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

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 multiplicative 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        1e+06      10^22
   mdl.He_II    frozen            0            0        1e+06      10^16
   mdl.C_I      thawed         33.1            0        1e+06      10^16
   mdl.C_II     frozen            0            0        1e+06      10^16
   mdl.C_III    frozen            0            0        1e+06      10^16
   mdl.N_I      thawed         8.32            0        1e+06      10^16
   mdl.N_II     frozen            0            0        1e+06      10^16
   mdl.N_III    frozen            0            0        1e+06      10^16
   mdl.O_I      thawed         67.6            0        1e+06      10^16
   mdl.O_II     frozen            0            0        1e+06      10^16
   mdl.O_III    frozen            0            0        1e+06      10^16
   mdl.Ne_I     thawed           12            0        1e+06      10^16
   mdl.Ne_II    frozen            0            0        1e+06      10^16
   mdl.Ne_III   frozen            0            0        1e+06      10^16
   mdl.Mg_I     thawed          3.8            0        1e+06      10^16
   mdl.Mg_II    frozen            0            0        1e+06      10^16
   mdl.Mg_III   frozen            0            0        1e+06      10^16
   mdl.Si_I     thawed         3.35            0        1e+06      10^16
   mdl.Si_II    frozen            0            0        1e+06      10^16
   mdl.Si_III   frozen            0            0        1e+06      10^16
   mdl.S_I      thawed         2.14            0        1e+06      10^16
   mdl.S_II     frozen            0            0        1e+06      10^16
   mdl.S_III    frozen            0            0        1e+06      10^16
   mdl.Ar_I     thawed         0.25            0        1e+06      10^16
   mdl.Ar_II    frozen            0            0        1e+06      10^16
   mdl.Ar_III   frozen            0            0        1e+06      10^16
   mdl.Ca_I     thawed         0.22            0        1e+06      10^16
   mdl.Ca_II    frozen            0            0        1e+06      10^16
   mdl.Ca_III   frozen            0            0        1e+06      10^16
   mdl.Fe       thawed         3.16            0        1e+06      10^16
   mdl.redshift frozen            0           -1           10           

ATTRIBUTES

The attributes for this object are:

Attribute Definition
H The equivalent hydrogen column (in units of 10^22 atoms/cm^2).
He_II, C_I, C_II, C_III, N_I, N_II, N_III, O_I, O_II, O_III, Ne_I, Ne_II, Ne_III, Mg_I, Mg_II, Mg_III, Si_I, Si_II, Si_III, S_I, S_II, S_III, Ar_I, Ar_II, Ar_III, Ca_I, Ca_II, Ca_III, Fe The column for the species (in units of 10^16 atoms/cm^2).
redshift The redshift of the absorber.

References

Changes in CIAO

Changed in CIAO 4.16

All species names now have the form <element>_<state>, such as He_II and Ca_III. The old versions (HeII and CaIII) can still be used but a deprecation warning may be displayed.

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.