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
- [1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XScosmo.html Note that this may refer to a newer version than the compiled version used by Sherpa; use `get_xsversion` to check.
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
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