Last modified: December 2020

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/set_xscosmo.html
AHELP for CIAO 4.13 Sherpa v1

set_xscosmo

Context: modeling

Synopsis

Set the cosmological parameters used by X-Spec models.

Syntax

set_xscosmo(h0, q0, l0)

h0 - number
q0 - number
l0 - number

Description

Set the cosmological parameters (H_0, q_0, lambda_0) used by X-Spec. It is equivalent to the X-Spec cosmo command [1] . The default values are h0=70, q0=0, and l0=0.73


Example

>>> set_xscosmo(73, 0, 0.73)

PARAMETERS

The parameters for this function are:

Parameter Definition
h0 The Hubble constant in km/s/Mpc.
q0 The deceleration parameter.
l0 The cosmological constant. If this is non-zero then the q0 parameter is ignored and the Universe is assumed to be flat.

References

XSPEC version

CIAO 4.13 comes with support for version 12.10.1s of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec;
print(xspec.get_xsversion())'
12.10.1s

Bugs

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

See Also

confidence
set_conf_opt, set_covar_opt, set_proj_opt
data
get_bkg_chisqr_plot, get_bkg_delchi_plot, get_bkg_fit_plot, get_bkg_model_plot, get_bkg_plot, get_bkg_ratio_plot, get_bkg_resid_plot, get_bkg_source_plot, set_areascal, set_arf, set_backscal, set_bkg, set_coord, set_counts, set_data, set_dep, 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_num_par_frozen, get_num_par_thawed, get_order_plot, get_par, get_pileup_model, get_source, get_source_component_image, get_source_component_plot, get_source_contour, get_source_image, get_source_plot, get_xsabund, get_xscosmo, get_xsxsect, get_xsxset, image_model, image_model_component, image_source, image_source_component, integrate, link, load_table_model, load_template_interpolator, load_template_model, load_user_model, normal_sample, reset, save_model, save_source, set_bkg_model, set_bkg_source, set_full_model, set_model, set_model_autoassign_func, set_par, set_pileup_model, set_source, set_xsabund, set_xsxsect, set_xsxset, t_sample, uniform_sample
plotting
get_cdf_plot, get_pdf_plot, 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, image_setregion