Last modified: December 2018

AHELP for CIAO 4.12 Sherpa v1


Context: models


reflection from neutral material. XSpec convolution model *Experimental*.


Convolution model for reflection from neutrial material according to the method of Magdziarz & Zdziarski (1995, MNRAS, 273, 837). This is a generalization of the pexrav and bexrav models. The reflection component alone can be obtained for

|rel_refl| < 0

then the actual reflection normalization is |rel_refl|. Note that you need to change then the limits of |rel_refl| excluding zero (as then the direct component appears). If

E_c = 0

, there is no cutoff in the power law. The metal and iron abundance are variable with respect to those set by the command set_xsabund. The opacities are those set by the command set_xsxsect. As expected in AGNs, H and He are assumed to be fully ionized.

When using this model it is essential to extend the energy range over which the model is calculated because photons at higher energies are Compton down-scattered into the target energy range. Please contact the CXC HelpDesk if you need to do this. The upper limit on the energies should be set above that for which the input spectrum has significant flux. To speed up the model, calculation of the output spectrum can be limited to energies below a given value by using set-xset to define REFLECT_MAX_E (in units of keV). For instance, suppose that the original data extends up to 100 keV. To accurately determine the reflection it may be necessary to extend the energy range up to 500 keV. Now to avoid calculating the output spectrum between 100 and 500 keV use the command

sherpa> set_xsxset('REFLECT_MAX_E', 100.0)

The core of this model is a Greens' function integration with one numerical integral performed for each model energy. The numerical integration is done using an adaptive method which continues until a given estimated fractional precision is reached. The precision can be changed by setting REFLECT_PRECSION. The default precision is 0.01 (i.e. 1%).

xsreflect Parameters

Number Name Description
1 rel_refl reflection scaling factor (1 for isotropic source above disk)
2 Redshift redshift
3 abund abundance of elements heavier than He relative to the solar abundances
4 Fe_abund iron abundance relative to the above
5 cosIncl cos i, the inclination angle

Loading the X-Spec convolution models

Please see ahelp xsconvolve for information on how to load the model.


XSpec version

This information is taken from the XSpec User's Guide. Version 12.10.0e of the XSpec models is supplied with CIAO 4.11.

About Contributed Software

This script is not an official part of the CIAO release but is made available as "contributed" software via the CIAO scripts page. Please see this page for installation instructions - such as how to ensure that the parameter file is available.


For a list of known bugs and issues with the XSPEC models, please visit the XSPEC bugs page.

See Also

list_model_components, list_models, load_xscflux, load_xsclumin, load_xscpflux, load_xsgsmooth, load_xsireflect, load_xskdblur, load_xskdblur2, load_xskerrconv, load_xslsmooth, load_xspartcov, load_xsrdblur, load_xsrfxconv, load_xsrgsxsrc, load_xssimpl, load_xsvashift, load_xsvmshift, load_xsxilconv, load_xszashift, load_xszmshift, models, tablemodel, xs, xsconvolve