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Last modified: December 2015

URL: http://cxc.harvard.edu/sherpa/ahelp/set_xsxsect.html
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AHELP for CIAO 4.9 Sherpa v1

set_xsxsect

Context: modeling

Synopsis

Set XSPEC photoelectric cross-section

Syntax

set_xsxsect(cross-section)
get_xsxsect()

Description

The set_xsxsect command sets the photoelectric cross-section used in XSPEC absorption models. The get_xsxsect command returns the current setting.

Available Cross-sections

Name Description
bcmc default value; Balucinska-Church & McCammon (1992, ApJ 400, 699) with a new He cross-section based on (1998, ApJ 496, 1044)
obcm bcmc with the old He cross-section
vern Verner et al. (1996, ApJ 465, 487)

XSPEC version

This information is taken from the XSPEC User's Guide. Version 12.9.0o of the XSPEC models is supplied with CIAO 4.9.

Example

sherpa> print get_xsxsect()
bcmc
sherpa> set_xsxsect("vern")
Cross Section Table set to vern: Verner, Ferland, Korista, and Yakovlev
1996

The current cross-section setting is retrieved ("bcmc", the default). It is then changed to "vern".

Bugs

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

To check the X-Spec version used by Sherpa, use the get_xsversion routine from the xspec module:

sherpa> from sherpa.astro.xspec import get_xsversion
sherpa> get_xsversion()
'12.9.0o'

See Also

confidence
set_conf_opt, set_covar_opt, set_proj_opt
data
get_bkg_plot, set_areascal, set_arf, set_backscal, set_bkg, set_coord, set_counts, set_data, set_exposure, set_grouping, set_quality, set_rmf, set_staterror, set_syserror
filtering
set_filter
info
list_model_ids, show_bkg_model, show_bkg_source
methods
set_iter_method, set_iter_method_opt, set_method, set_method_opt
modeling
add_model, add_user_pars, clean, create_model_component, delete_bkg_model, delete_model, delete_model_component, get_model, get_model_autoassign_func, get_model_component, get_model_component_image, get_model_component_plot, get_model_plot, get_num_par, get_order_plot, get_par, get_pileup_model, get_source, get_source_component_image, get_source_component_plot, image_model, image_model_component, image_source, image_source_component, integrate, integrate1d, link, load_table_model, load_template_model, load_user_model, normal_sample, reset, save_model, save_source, set_bkg_model, set_full_model, set_model_autoassign_func, set_par, set_pileup_model, set_source, set_xsabund, set_xscosmo, set_xsxset, t_sample, uniform_sample
plotting
get_lrt_plot, get_lrt_results, get_pvalue_plot, get_pvalue_results, plot_cdf, plot_model, plot_model_component, plot_pdf, plot_pvalue, plot_scatter, plot_source, plot_source_component, plot_trace
psfs
delete_psf, load_conv
saving
save_delchi, save_resid
statistics
set_prior, set_sampler, set_sampler_opt, set_stat
utilities
calc_chisqr, calc_energy_flux, calc_model_sum, calc_photon_flux, calc_source_sum, calc_stat, eqwidth, set_analysis, set_default_id
visualization
contour_model, contour_ratio, contour_resid, get_ratio, get_resid, image_setregion

Last modified: December 2015
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