Last modified: December 2023

AHELP for CIAO 4.16 Sherpa


Context: models


The XSPEC sirf model: self-irradiated funnel.



The xssirf model is an additive model component.


The model is described at [1] .


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

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

   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.tin      thawed            1         0.01         1000        keV
   mdl.rin      thawed         0.01        1e-06           10       rsph
   mdl.rout     thawed          100          0.1        1e+08       rsph
   mdl.theta    thawed         22.9            0           90        deg
   mdl.incl     frozen            0          -90           90        deg
   mdl.valpha   frozen         -0.5         -1.5            5           
   mdl.gamma    frozen        1.333          0.5           10           
   mdl.mdot     frozen         1000          0.5        1e+07           
   mdl.irrad    frozen            2            0           20           
   mdl.norm     thawed            1            0        1e+24           


The attributes for this object are:

Attribute Definition
tin The inner temperature (at the inner, inside-the-funnel photosphere), in keV.
rin The inner (inner, inside-the-fulle photosphere) radius in "spherisation radius" units (see [1] for details).
rout The outer photosphere radius in "spherisation radius" units
theta The half-opening angle of the cone, in degrees.
incl The inclination angle of the funnel, in degrees. Affects mainly self-occultation and relativistic boost effects.
valpha The velocity law exponent.
gamma The adiabatic index. It affects the inner, hotter parts of the flow, therefore we set is to 4/3 by default.
mdot The mass ejection rate in Eddington (critical) units.
irrad The number of iterations for irradiation.
norm The normalization of the model.


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;


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