    The XSPEC eqpair model: Paolo Coppi's hybrid (thermal/non-thermal) hot plasma emission models.

xseqpair
The xseqpair model is an additive model component.

The model is described at [1] .

The l_hl_s , l_ntl_h , and abhe parameters have been renamed to l_hovl_s , l_ntol_h , and ab_met respectively to match the XSPEC definition. The names l_hl_s , l_ntl_h , and abhe can still be used to access the parameters, but they will be removed in a future release.

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

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

mdl Param Type Value Min Max Units ----- ---- ----- --- --- ----- mdl.l_hovl_s thawed 1 1e-06 1e+06 mdl.l_bb thawed 100 0 10000 mdl.kT_bb frozen 200 1 400000 eV mdl.l_ntol_h thawed 0.5 0 0.9999 mdl.tau_p frozen 0.1 0.0001 10 mdl.radius frozen 1e+07 100000 1e+16 cm mdl.g_min frozen 1.3 1.2 1000 mdl.g_max frozen 1000 5 10000 mdl.G_inj frozen 2 0 5 mdl.pairinj frozen 0 0 1 mdl.cosIncl frozen 0.5 0.05 0.95 mdl.Refl frozen 1 0 2 mdl.Fe_abund frozen 1 0.1 10 mdl.Ab_met frozen 1 0.1 10 mdl.T_disk frozen 1e+06 10000 1e+06 K mdl.xi thawed 0 0 5000 mdl.Beta frozen -10 -10 10 mdl.Rin frozen 10 6.001 10000 M mdl.Rout frozen 1000 0 1e+06 M mdl.redshift frozen 0 0 4 mdl.norm thawed 1 0 1e+24

ATTRIBUTES

The attributes for this object are:

Attribute
Definition
l_hovl_s
The ratio of the hard to soft compactness, l_h / l_s.
l_bb
The soft photon compactness.
kT_bb
The temperature of the blackbody if greater than 0. When less than zero then the absolute value is used as the T_max parameter of the xsdispkpn model. The units are in eV.
l_ntol_h
The fraction of power supplied to energetic particles which goes into accelerating non-thermal particles, l_nt / l_h.
tau_p
The Thomson scattering depth.
radius
The size of the scattering region in cm.
g_min
The minimum Lorentz factor of the pairs.
g_max
The maximum Lorentz factor of the pairs.
G_inj
If less than zero then the non-thermal spectrum is assumed mono-energetic at g_max, otherwise a power law is used from g_min to g_max.
pairinj
If zero then accelerated particles are electrons from thermal pool. If one then accelerated particles are electrons and positrons.
cosIncl
The cosine of the inclination angle of the reflecting material to the line of sight.
Refl
The fraction of the scattering region's emission intercepted by reflecting material.
Fe_abund
The iron abundance with respect to solar.
Ab_met
The abundance of the other metals with respect to solar.
T_disk
The temperature of the reflecting disk, in K.
xi
The ionization parameter of the reflector.
Beta
The power-law index with radius of disk reflection emissivity.
Rin
The inner radius of the reflecting material, in units of GM/c^2.
Rout
The outer radius of the reflecting material, in units of GM/c^2.
redshift
The redshift of the source.
norm
The normalization of the model: see [1] for more details.

Notes

The precision of the numerical integration can be changed by using the set_xsxset function to set the value of the EQPAIR_PRECISION keyword, which defines the fractional precision. The default is 0.01 (1%).

References

[1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelEqpair.html

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

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

December 2023