Chandra X-Ray Observatory
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Last modified: 15 December 2016

Alphabetical List of Ahelp Files


    Topic Context Summary
A absorptionedge models Optical model of an absorption edge defined in Angstroms.
absorptiongaussian models A Gaussian model of an absorption feature expressed in equivalent width and defined in Angstroms.
absorptionlorentz models A Lorentz model of an absorption feature expressed in equivalent width and defined in Angstroms.
absorptionvoigt models A Voigt model of an absorption feature defined in Angstroms.
accretiondisk models A model of emission due to an accretion disk.
add_model modeling Add a user-defined model class as a Sherpa model type
add_user_pars modeling Add parameters to a user-defined model
atten models Attenuation by ISM.

B bbodyfreq models Blackbody as a function of frequency.
bbody models Blackbody as a function of energy.
beta1d models 1-D Lorentz model with a varying power law.
beta2d models 2-D Lorentz model with a varying power law.
blackbody models Blackbody function
box1d models 1-D box function.
box2d models 2-D box function.
bpl1d models Broken power law function.
bremsstrahlung models Bremsstrahlung function
brokenpowerlaw models Broken power-law function

C calc_chisqr utilities Calculate the Chi Squared statistic contribution per bin
calc_data_sum2d utilities Calculate the sum of observed image counts
calc_data_sum utilities Calculate the sum of observed data counts
calc_energy_flux utilities Calculate the unconvolved model energy flux
calc_ftest utilities Calculate the significance using the F test
calc_kcorr utilities Calculate the k correction for a spectral model.
calc_mlr utilities Calculate the Maximum Likelihood Ratio test
calc_model_sum2d utilities Calculate the convolved 2D model amplitudes
calc_model_sum utilities Calculate the sum of convolved model counts
calc_photon_flux utilities Calculate the unconvolved model photon flux
calc_source_sum2d utilities Calculate the unconvolved 2D model amplitudes
calc_source_sum utilities Calculate the sum of unconvolved model amplitudes
calc_stat_info fitting Returns goodness-of-fit statistics associated with a Sherpa data set.
calc_stat utilities Calculate the fit statistic by data set ID
cash statistics A maximum likelihood function.
ccm models Interstellar extinction function
chi2constvar statistics Chi-square statistic with constant variance computed from the counts data.
chi2datavar statistics Chi-square statistic with variance computed from the data.
chi2gehrels statistics Chi-square statistic with the Gehrels variance function.
chi2modvar statistics Chi-square statistic with variance computed from model amplitudes.
chi2xspecvar statistics Chi-square statistic with variance computed from data amplitudes.
chisquare statistics About the chi-square statistic.
clean modeling Erase data and model settings in a Sherpa session
conf confidence Estimate confidence intervals for selected thawed parameters based on confidence method
const1d models 1-D constant amplitude model.
const2d models 2-D constant amplitude model.
contour_data visualization Open a contour plot of a data set in ChIPS
contour_fit_resid visualization Create a contour plot of the fit and residuals
contour_fit visualization Send a contour plot of the fit
contour_kernel psfs Create a contour plot of a PSF kernel
contour_model visualization Open a contour plot of a data set model in ChIPS
contour_psf psfs Create a contour plot of a PSF
contour_ratio visualization Open a contour plot of a data-to-model ratio in ChIPS
contour_resid visualization Open a contour plot of data-minus-model residuals in ChIPS
contour_source visualization Create a contour plot of the source
contour visualization Open a contour plot in ChIPS
copy_data data Copy a data set by data ID to a new data ID (deep copy)
cos models Cosine function.
covariance confidence Estimate confidence intervals for selected thawed parameters based on covariance method
create_model_component modeling Create a new model component
cstat statistics A maximum likelihood function from XSPEC

D dataspace1d data Create a blank 1D dataset
dataspace2d data Create a blank 2D dataset
datastack data Sherpa extension package for modeling stacks of data.
delete_bkg_model modeling Delete a background model
delete_data data Delete a data set by ID
delete_model_component modeling Delete a model component
delete_model modeling Delete a Sherpa model by model ID
delete_psf psfs Delete a PSF model
delta1d models 1-D delta function.
delta2d models 2-D delta function.
dered models Dereddening function.
devaucouleurs2d models DeVaucouleurs profile.
disk2d models Uniform 2-D Disk model.

E edge models Photoabsorption edge model.
emissiongaussian models A Gaussian model of an emission feature defined in Angstroms.
emissionlorentz models A Lorentz model of an emission feature defined in Angstroms.
emissionvoigt models Voigt model of an emission feature defined in Angstroms.
eqwidth utilities Calculate the equivalent width of an emission or absorption line.
erfc models A 1-D complementary error function.
erf models A 1-D error function.
estimate_weighted_expmap contrib Return the estimated exposure map value by weighting an ARF by a spectral model.
exp10 models Exponential function, base 10.
exp models Exponential function.

F fake_pha data Simulate an observed spectrum based on a theoretical model.
fake data Simulate a generic data set with a chosen model and add noise
fit fitting Perform a fit using current optimization method and fit statistic.
fm models Fitzpatrick and Massa extinction curve
freeze modeling Freeze model parameters, so they do not vary during a fit.

G gamma utilities Calculate the Gamma function
gauss1d models 1-D unnormalized Gaussian function.
gauss2d models 2-D unnormalized Gaussian function.
get_analysis utilities Return the current units setting for a PHA data set
get_areascal data Return the source or background pixel fractional area scale
get_arf_plot data Return the data and preferences defining an ARF plot
get_arf data Return a source or background ARF by data set ID
get_axes data Return the alternate grid of a data set
get_backscal data Return the source or background extraction region area
get_bkg_plot data Return the data and preferences defining a background plot.
get_bkg_scale data Returns the complete background scaling factor
get_bkg data Return the background data, ARF, RMF, or model.
get_chart_spectrum contrib Return the model spectrum in the form required by ChaRT2
get_chisqr_plot statistics Return the data and preferences defining a chi^2 plot
get_conf confidence Return information regarding the confidence method.
get_coord data Return the coordinate system of an image
get_counts data Return the dependent variable array (e.g., counts) of a data set
get_covar confidence Return settings or results for the covariance method.
get_data_plot data Return a plot, contour, or image of the data, or the associated preferences
get_data_prof_prefs contrib The plot preferences for radial or elliptical profiles of imaging data.
get_data_prof contrib Return the data used to create the radial or elliptical profile of imaging data.
get_data data Return details of a Sherpa data set by ID.
get_default_id info Return the default data set ID in a Sherpa session.
get_delchi_plot statistics Return the data and preferences defining a delta chi plot
get_delchi_prof_prefs contrib The plot preferences for radial or elliptical profiles of the residuals (data - model)/error to imaging data.
get_delchi_prof contrib Return the data used to create the radial or elliptical profile of the residuals (data - model)/error to imaging data.
get_dep data Return the dependent variable array (e.g., counts) of a data set
get_dims data Return the length of the x-dimension of a data set
get_draws methods Run the pyBLoCXS MCMC-based algorithm using the current sampler.
get_energy_flux_hist plotting Calculate a histogram of a simulated energy flux probability distribution
get_error data Return the total errors on the counts of a data set
get_exposure data Return the exposure time for a source or background data set
get_filter filtering Return the filter of a data set
get_fit_prof contrib Return the data used to create the radial or elliptical profile of fits to imaging data.
get_fit fitting Return model fit information associated with a Sherpa data set.
get_grouping data Obtain the grouping flags from a data set
get_indep data Return the independent variable array of a data set
get_instmap_weights contrib Return the model spectrum in the form required by the spectrumfile parameter of mkinstmap
get_int_proj confidence Return the confidence data defining an interval projection plot
get_int_unc confidence Return the confidence data defining an int_unc() plot
get_iter_method_name methods Return the name of the current iterative fitting method
get_iter_method_opt methods Return the value of the specified option for the current iterative fitting method
get_kernel psfs Return kernel plot, image, and contour preferences.
get_lrt_plot plotting Access a histogram plot of likelihood ratio test results.
get_lrt_results plotting Access the simulation results of the likelihood ratio test.
get_method methods Return information on the optimization method
get_model_autoassign_func modeling Return the method for storing model identifiers
get_model_component_image modeling Returns the 2D data and coordinate settings defining the convolved model component image
get_model_component_plot modeling Returns the data and preferences defining the convolved model component plot
get_model_component modeling Returns the parameters for the specified model component
get_model_plot modeling Return a plot, contour, or image of a model, or the associated preferences
get_model_prof_prefs contrib The plot preferences for radial or elliptical profiles of the model (after any PSF convolution) for imaging data.
get_model_prof contrib Return the data used to create the radial or elliptical profile of the source model (after any PSF convolution) for imaging data.
get_model modeling Return the model, model parameters, or model type
get_num_par modeling Returns the number of parameters (total, frozen, or thawed) in a model.
get_order_plot modeling Return the data and preferences defining a plot of model spectral orders
get_par modeling Returns a model parameter.
get_photon_flux_hist plotting Calculate a histogram of a simulated photon flux probability distribution
get_pileup_model modeling Return the pileup model associated with a data set.
get_prior statistics Access the prior function associated with a Sherpa model parameter.
get_proj confidence Return information regarding the projection method.
get_psf psfs Return PSF model data and plot, image, and contour preferences.
get_pvalue_plot plotting Access a histogram plot of likelihood ratio test results.
get_pvalue_results plotting Access the simulation results of the likelihood ratio test.
get_quality data Obtain the quality flags from a data set
get_rate utilities Return the measured count rate of a data set
get_ratio visualization Return information on the ratio of data and model.
get_reg_proj confidence Return the confidence data defining a region projection contour plot
get_reg_unc confidence Return the confidence data defining a reg_unc() contour plot
get_resid_prof_prefs contrib The plot preferences for radial or elliptical profiles of the residuals (data - model) to imaging data.
get_resid_prof contrib Return the data used to create the radial or elliptical profile of the residuals (data - model) to imaging data.
get_resid visualization Return information on a contour plot of the residuals of data and model.
get_response modeling Get the associated instrument response model of a PHA data set by data ID
get_rmf data Return a source or background RMF by data set ID
get_sampler statistics Return information on the current pyBLoCXS sampler.
get_source_component_image modeling Returns the 2D data and coordinate settings defining the unconvolved model component image
get_source_component_plot modeling Returns the data and preferences defining the unconvolved model component plot
get_source_prof_prefs contrib The plot preferences for radial or elliptical profiles of the source model for imaging data.
get_source_prof contrib Return the data used to create the radial or elliptical profile of the source model (before any PSF convolution) for imaging data.
get_source modeling Return the unconvolved model associated with a Sherpa data set ID.
get_specresp data Return the effective area of a PHA spectrum
get_split_plot plotting Return plot attributes for multiple plots
get_staterror data Return the statistical errors on the counts of a data set
get_stat_info fitting Parses the goodness-of-fit statistic information returned by calc_stat_info()
get_stat statistics Return information on the fit statistic
get_syserror data Return the systematic errors on the counts of a data set
gridsearch methods Grid searching optimization method
group data Enable and specify the grouping settings of a spectral data set
guess modeling Estimate initial parameter values and ranges

H histogram1d visualization Create a 1D histogram from a binned grid and array of samples
histogram2d visualization Create a 2D histogram from a pair of axes and a pair of sample arrays
hubblereynolds models Hubble-Reynolds profile.

I igamc utilities Calculate the complement of the regularized incomplete Gamma function (upper)
igam utilities Calculate the regularized incomplete Gamma function (lower)
ignore2d_id filtering Apply an exclude region filter to 2-D data by data set ID(s).
ignore2d filtering Apply an exclude region filter to all 2-D data sets
ignore_bad filtering Ignore bins according to quality flags
ignore_id filtering Apply an exclude filter to 1-D data by data set ID
ignore filtering Apply an exclude filter to all 1D data sets
image_close visualization Close the imager window (i.e., exit ds9).
image_data visualization Send image of 2-D data to ds9.
image_deleteframes visualization Delete frames in the imager window (ds9).
image_fit visualization Send image of the fit results to ds9.
image_getregion visualization Returns a region description from ds9.
image_kernel psfs Send a PSF kernel image to the imager (ds9).
image_model_component modeling Sends image of the convolved model component to ds9.
image_model modeling Send image of the model to ds9.
image_open visualization Open the imager window (i.e., start ds9).
image_psf psfs Send a PSF image to the imager (ds9).
image_ratio visualization Send image of the ratio (i.e., data/model) to ds9.
image_resid visualization Send image of the residuals (i.e., data - model) to ds9.
image_setregion visualization Sends a region description to ds9, where it is drawn in the current frame.
image_source_component modeling Sends image of the unconvolved model component to ds9.
image_source modeling Image the 2-D unconvolved model
image_xpaget visualization Retrieve data from ds9 using XPA.
image_xpaset visualization Send data to ds9 using XPA.
incbet utilities Calculate the incomplete Beta function
integrate1d modeling Helper function to control the integration of 1D non-XSPEC model expressions
integrate modeling Controlling the integration of model components
int_proj confidence Create a confidence plot of fit statistic vs. parameter value.
int_unc confidence Create a confidence plot of fit statistic vs. parameter value.

J jdpileup models A CCD pileup model developed by John Davis of MIT.

L leastsq statistics Chi-square statistic with variance set to 1.
levmar methods Levenberg-Marquardt optimization method
lgam utilities Calculate the log of the Gamma function
linebroad models Line-broadening profile.
link modeling Link a model parameter to another model parameter.
list_bkg_ids info List all background IDs associated with a data set.
list_data_ids info List all data set IDs in a Sherpa session.
list_functions info List all available Sherpa functions
list_iter_methods methods List all Sherpa iterative fitting methods.
list_methods methods List all Sherpa optimization methods.
list_models models List all Sherpa models.
list_model_components models List all models established in a Sherpa session.
list_model_ids info List all current model IDs.
list_priors statistics List thawed Sherpa model parameters with associated priors.
list_response_ids info List all response IDs associated with a data set.
list_samplers statistics List all available pyBLoCXS samplers.
list_stats info List all Sherpa fit statistics.
lmc models Extinction curve for the Large Magellanic Cloud
lmod contrib Load a X-Spec local model, compiled with convert_xspec_user_model, into Sherpa
load_arf data Load a source or background ARF
load_arrays data Load data from variables containing arrays.
load_ascii data Load ASCII data
load_bkg_arf data Load a background ARF
load_bkg_rmf data Load a background RMF
load_bkg data Load a PHA background spectrum
load_conv psfs Load a 1D convolution kernel
load_data data Load 1D data from a file
load_filter filtering Load filter from a FITS table, FITS image, or ASCII file
load_grouping data Load a grouping scheme from a FITS table or ASCII file
load_image data Load an image
load_multi_arfs data Load multiple ARFs
load_multi_rmfs data Load multiple RMFs
load_pha data Load PHA source spectra
load_psf psfs Load a PSF model
load_quality data Load quality flags from a FITS table or ASCII file
load_rmf data Load a source or background RMF
load_staterror data Load statistical errors
load_syserror data Load systematic errors
load_table_model modeling Load a table model, including X-Spec atable and mtable forms
load_table data Load tabular data
load_template_model modeling Load a set of template models
load_user_model modeling Load a user-defined model
load_user_stat statistics Load a user-defined fit statistic
load_xscflux models calculate flux. XSpec convolution model *Experimental*.
load_xsgsmooth models gaussian smoothing. XSpec convolution model *Experimental*.
load_xsireflect models reflection from ionized material. XSpec convolution model *Experimental*.
load_xskdblur2 models convolve with the laor2 model shape. XSpec convolution model *Experimental*.
load_xskdblur models convolve with the laor model shape. XSpec convolution model *Experimental*.
load_xskerrconv models accretion disk line shape with BH spin as free parameter. XSpec convolution model *Experimental*.
load_xslsmooth models lorentzian smoothing. XSpec convolution model *Experimental*.
load_xspartcov models partial covering. XSpec convolution model *Experimental*.
load_xsrdblur models convolve with the dislkine model shape. XSpec convolution model *Experimental*.
load_xsreflect models reflection from neutral material. XSpec convolution model *Experimental*.
load_xssimpl models comptonization of a seed spectrum. XSpec convolution model *Experimental*.
load_xszashift models Redshift an additive model. XSpec convolution model *Experimental*.
load_xszmshift models Redshift a multiplicative model. XSpec convolution model *Experimental*.
log10 models Logarithm function, base 10.
logabsorption models Logarithmic Gaussian absorption model expressed in optical depth and defined in Angstroms.
logemission models Logarithmic Gaussian emission model defined in Angstroms.
logparabola models Log-parabolic function
log models Natural logarithm function.
lorentz1d models 1-D normalized Lorentzian function.
lorentz2d models 2-D unnormalized Lorentzian function.

M models models Summary of Available Models
moncar methods Monte Carlo optimization method

N neldermead methods Nelder-Mead Simplex optimization method
normal_sample modeling Sample the current set of thawed parameters from a uni-variate or multi-variate normal distribution.
normbeta1d models 1-D normalized beta function.
normgauss1d models 1-D normalized Gaussian function.
normgauss2d models 2-D normalized Gaussian function.
notice2d_id filtering Apply an include filter to 2D data by dataset id
notice2d filtering Apply an include filter to all 2D datasets
notice_id filtering Apply an include filter to 1D data by dataset id
notice filtering Apply an include filter to all 1D datasets

O opticalgaussian models Gaussian model of an absorption feature expressed in optical depth and defined in Angstroms.

P pack_image data Pack image data into an IMAGECrate
pack_pha data Pack PHA data into a PHACrate
pack_table data Pack tabular data into a TABLECrate
paramprompt modeling Toggle parameter prompting for initial model values
plot_arf plotting Plot an ARF
plot_bkg plotting Plot information about background data
plot_cdf plotting Plot a cumulative distribution function with lower, median, and upper quantiles.
plot_chart_spectrum contrib Plot up the model spectrum in the form required by ChaRT
plot_chisqr plotting Plot the chi-squared statistic
plot_data plotting Plot the dataset
plot_delchi plotting Plot the delchi residuals of the fit: (data-model)/error
plot_energy_flux plotting Plot the calculated energy flux distribution
plot_fit plotting Plot the fit, fit plus delta chi, or fit plus residuals
plot_instmap_weights contrib Plot up the model spectrum in the form required by mkinstmap
plot_kernel psfs Plot the PSF kernel
plot_model_component plotting Plots individual convolved source model components
plot_model plotting Plot the convolved source model
plot_order plotting Plot the convolved source model by order
plot_pdf plotting Plot a binned probability density function.
plot_photon_flux plotting Plot the calculated photon flux distribution
plot_psf psfs Plot the PSF
plot_pvalue plotting Plot a histogram of likelihood ratio test results.
plot_ratio plotting Plot the (data/model) ratio
plot_resid plotting Plot the residuals of the fit: (data - model)
plot_scatter plotting Create an X,Y scatter plot.
plot_source_component plotting Plots individual unconvolved source model components
plot_source plotting Plot the unconvolved source model
plot_trace plotting Create a trace plot of iteration number vs. sampled value.
plot plotting Plot multiple objects (data, model, residuals, etc.)
poisson models Poisson function.
polynom1d models 1-D polynomial function.
polynom2d models 2-D polynomial function.
polynomial models 1-D polynomial function of order <= 5
powerlaw models Power law function
powlaw1d models 1-D power law.
prof_data contrib Plot a radial or elliptical profile of imaging data.
prof_delchi contrib Plot a radial or elliptical profile of the residuals (data - model)/error to imaging data.
prof_fit_delchi contrib Plot a radial or elliptical profile of the fit (data and model) and residuals (data-model)/error to imaging data.
prof_fit_resid contrib Plot a radial or elliptical profile of the fit (data and model) and residuals (data-model) to imaging data.
prof_fit contrib Plot a radial or elliptical profile of the fit (data and model) to imaging data.
prof_model contrib Plot a radial or elliptical profile of the model (after any PSF convolution) for imaging data.
prof_resid contrib Plot a radial or elliptical profile of the residuals (data - model) to imaging data.
prof_source contrib Plot a radial or elliptical profile of the source model for imaging data.
projection confidence Estimate confidence intervals for selected thawed parameters based on projection method
pyblocxs methods MCMC-based algorithm for Bayesian Low-Count X-ray Spectral (BLoCXS) analysis

R rebin visualization Rebin a histogram
recombination models Model of continuum emission due to recombination
reg_proj confidence Create a confidence contour of fit statistic vs. two thawed parameter values.
reg_unc confidence Create a confidence contour of fit statistic vs. two thawed parameter values.
renorm contrib Change the normalization of a model to match the data.
reset modeling Reset model parameter values after a fit
restore saving Restore a previous Sherpa session from a file

S sample_energy_flux utilities Sample the energy flux distribution
sample_flux utilities Return a sample of Sherpa model parameters and the corresponding unabsorbed energy flux and flux uncertainty
sample_photon_flux utilities Sample the photon flux distribution
save_all saving Save all the information about the current session
save_arrays saving Save a list of arrays as columns to a FITS table or ASCII file
save_chart_spectrum contrib Write out the model spectrum in the form required by ChaRT2
save_data saving Save a Sherpa data set to an ASCII file.
save_delchi saving Save the delta chi fit residuals to a FITS table or ASCII file
save_error saving Save total errors to a FITS table or ASCII file
save_filter saving Save filter to a FITS table or ASCII file
save_grouping saving Save grouping flags to a FITS table or ASCII file
save_image saving Save image data to a file
save_instmap_weights contrib Write out the model spectrum in the form required by mkinstmap
save_model modeling Save the convolved source model to a FITS table or ASCII file
save_pha saving Save a Sherpa data set to a PHA file.
save_quality saving Save quality flags to a FITS table or ASCII file
save_resid saving Save the simple data-model difference residuals
save_source modeling Save the unconvolved source model to a FITS table or ASCII file
save_staterror saving Save statistical errors to a FITS table or ASCII file
save_syserror saving Save systematic errors to a FITS table or ASCII file
save_table saving Save a Sherpa data set to a FITS or ASCII file.
save saving Save the current Sherpa session to a file
scale1d models 1-D constant amplitude model.
scale2d models 2-D constant amplitude model.
schechter models Schechter function.
script saving Save every command typed in a Sherpa or ChIPS session to a file.
seaton models Galactic extinction model
sersic2d models Sersic 2D surface brightness model.
set_analysis utilities Set the units for spectral analysis
set_areascal data Set the fractional area
set_arf data Set an ARF dataset
set_backscal data Set the extraction region area
set_bkg_model modeling Set a background model expression
set_bkg data Set a background PHA dataset
set_conf_opt confidence Set the options for confidence
set_coord data Set the image coordinate system
set_counts data Set the dependent variable (e.g. counts) of a dataset
set_covar_opt confidence Set the options for covariance
set_data data Set a source dataset
set_default_id utilities Set the default Sherpa data id
set_exposure data Set the exposure time
set_filter filtering Apply user-defined filter to a data set
set_full_model modeling Set the complete convolved source and background model expressions to be used for fitting a data set
set_grouping data Apply user-defined grouping to a dataset
set_iter_method_opt methods Set the value of the specified option for the current iterative fitting method
set_iter_method methods Set the iterative fitting method
set_method_opt methods Set the options of the chosen optimization method
set_method methods Set the optimization method
set_model_autoassign_func modeling Define a method for storing model identifiers
set_par modeling Set initial values for a model parameter
set_pileup_model modeling Set a pileup model to be used in fitting a dataset
set_prior statistics Define a prior function for a particular Sherpa model parameter.
set_proj_opt confidence Set the options for projection
set_psf psfs Convolve the PSF model with the source model
set_quality data Apply user-defined quality flags to a data set
set_rmf data Set an RMF dataset
set_sampler_opt statistics Define sampler options for a pyBLoCXS chain.
set_sampler statistics Set the current pyBLoCXS sampler.
set_source modeling Set the source model expression to be used for fitting a dataset
set_staterror data Set the statistical errors
set_stat statistics Set the statistical method
set_syserror data Set the systematic errors
set_xlinear plotting Changes the plot X axis to use a linear scale.
set_xlog plotting Changes the plot x axis to use a logarithmic scale.
set_xsabund modeling Set XSPEC solar abundance
set_xscosmo modeling Set XSPEC cosmology settings (H0, q0, L0)
set_xsxsect modeling Set XSPEC photoelectric cross-section
set_xsxset modeling Set and get environment variables for XSPEC models
set_ylinear plotting Changes the plot Y axis to use a linear scale.
set_ylog plotting Changes the plot Y axis to use a logarithmic scale.
shell2d models Homogeneous spherical shell, projected along the z-direction.
sherparc sherpa The .sherpa.rc file provides user-configuration options for Sherpa
sherpa_chart contrib Create and view spectral files for ChaRT2 (CIAO contributed package).
sherpa_contrib contrib Contributed CIAO routines for Sherpa.
sherpa_profiles contrib Radial profiles of imaging data in Sherpa (CIAO contributed package).
sherpa_utils contrib Utility routines for Sherpa (CIAO contributed package).
sherpa sherpa Introduction to Sherpa, the CIAO modeling and fitting package
show_all info Reports the current state of the Sherpa session
show_bkg_model info Display the background convolved model
show_bkg_source info Display the background unconvolved model
show_bkg info Display PHA background data set information
show_conf info Display the confidence information
show_covar info Display the covariance information
show_data info Display the data sets
show_filter filtering Display the filters applied to a dataset
show_fit info Display the fit information
show_kernel psfs Display the PSF kernel
show_method info Display the optimization method
show_model info Display the convolved source model
show_proj info Display the projection information
show_psf psfs Display the PSF model
show_source info Display the unconvolved source model
show_stat info Display the fit statistic
sigmagauss2d models 2-D unnormalized Gaussian function with independent axis parameterized by sigma.
sin models Sine function.
smc models Extinction curve for the Small Magellanic Cloud
sm models Galactic extinction curve
sqrt models Square root function.
stephi1d models 1-D step function.
steplo1d models 1-D step function.
subtract data Perform background subtraction

T tablemodel models Using an n-dimensional array of values as a model (table model).
tan models Tangent function.
thaw modeling Thaw model parameters so they vary during a fit
t_sample modeling Sample the current set of thawed parameters from a Student's t-distribution.

U ungroup data Ungroup PHA data
uniform_sample modeling Sample the current set of thawed parameters from a uniform distribution.
unlink modeling Remove a link between model parameters
unpack_arf data Unpack an ARF from an ARFCrate
unpack_arrays data Unpack arrays from a CrateData object
unpack_ascii data Unpack ASCII data from a crate
unpack_bkg data Unpack PHA data from a PHACrate
unpack_data data Unpack a table data, ASCII data, or a spectrum from a crate
unpack_image data Unpack image data from an IMAGECrate
unpack_pha data Unpack PHA data from a PHACrate
unpack_rmf data Unpack an RMF from a crate
unpack_table data Unpack tabular data from a TABLECrate
unsubtract data Undo background subtraction

W wstat statistics A maximum likelihood function from XSPEC

X xgal models Extragalactic extinction function
xsabsori models Ionized absorber. XSPEC model.
xsacisabs models Decay in the ACIS quantum efficiency. XSPEC model.
xsagauss models Gaussian line profile in wavelength space. XSPEC model.
xsapec models APEC thermal plasma model. XSPEC model.
xsbapec models APEC thermal plasma model with velocity broadening as a free parameter. XSPEC model.
xsbbodyrad models Blackbody spectrum with norm proportional to surface area. XSPEC model.
xsbbody models Blackbody spectrum. XSPEC model.
xsbexrav models E-folded broken power law reflected from neutral matter. XSPEC model.
xsbexriv models E-folded broken power law reflected from ionized matter. XSPEC model.
xsbkn2pow models Broken power law, two break energies. XSPEC model.
xsbknpower models Broken power law. XSPEC model.
xsbmc models Comptonization by relativistically moving matter. XSPEC model.
xsbremss models Thermal bremsstrahlung. XSPEC model.
xsbvapec models APEC thermal plasma model with variable abundances and velocity broadening as a free parameter. XSPEC model.
xsbvvapec models APEC thermal plasma model with variable abundances and velocity broadening as a free parameter. XSPEC model.
xsc6mekl models 6th-order Chebyshev polynomial DEM using mekal. XSPEC model.
xsc6pmekl models Exponential of 6th-order Chebyshev polynomial DEM using mekal. XSPEC model.
xsc6pvmkl models Variable abundance version of c6pmekl. XSPEC model.
xsc6vmekl models Variable abundance version of xsc6mekl. XSPEC model.
xscabs models Compton scattering (non-relativistic). XSPEC model.
xscemekl models Multi-temperature mekal. XSPEC model.
xscevmkl models Multi-temperature vmeka. XSPEC model.
xscflow models Cooling flow model. XSPEC model.
xscompbb models Comptonized blackbody spectrum after Nishimura et al. (1986). XSPEC model.
xscompls models Comptonization spectrum after Lamb and Sanford (1979). XSPEC model.
xscompmag models Thermal and bulk Comptonization for cylindrical accretion onto the polar cap of a magnetized neutron star. XSPEC model.
xscompps models Comptonization, Poutanen and Svenson. XSPEC model.
xscompst models Comptonization spectrum after Sunyaev and Titarchuk (1980). XSPEC model.
xscomptb models Thermal and bulk Comptonization of a seed blackbody-like spectrum. XSPEC model.
xscompth models Component of Paolo Coppi's hybrid (thermal/non-thermal) hot plasma emission models.
xscomptt models Comptonization spectrum after Titarchuk (1994). XSPEC model.
xsconstant models Energy-independent multiplicative factor. XSPEC model.
xsconvolve models The XSpec convolution models *Experimental*.
xscplinear models Non-physical piecewise-linear model for low count background spectra. XSPEC model.
xscutoffpl models Power law with high energy exponential cutoff. XSPEC model.
xscyclabs models Cyclotron absorption line. XSPEC model.
xsdiskbb models Multiple blackbody disk model. XSPEC model.
xsdiskir models Irradiated inner and outer disk. XSPEC model.
xsdiskline models Line emission from relativistic accretion disk. XSPEC model.
xsdiskm models Disk model with gas pressure viscosity. XSPEC model.
xsdisko models Modified blackbody disk model. XSPEC model.
xsdiskpbb models Accretion disk, power-law dependence for T(r). XSPEC model.
xsdiskpn models Accretion disk around a black hole. XSPEC model.
xsdisk models Disk model. XSPEC model.
xsdust models Dust scattering out of the beam. XSPEC model.
xsedge models Absorption edge. XSPEC model.
xseplogpar models Log-parabolic blazar model with nu Fu normalization. XSPEC model.
xseqpair models Component of Paolo Coppi's hybrid (thermal/non-thermal) hot plasma emission models
xseqtherm models Component of Paolo Coppi's hybrid (thermal/non-thermal) hot plasma emission models
xsequil models Equilibrium ionization collisional plasma model from Borkowski. XSPEC model.
xsexpabs models Low-energy exponential cutoff. XSPEC model.
xsexpdec models An exponential decay. XSPEC model.
xsexpfac models Exponential factor. XSPEC model.
xsezdiskbb models Multiple blackbody disk model with zero-torque inner boundary. XSPEC model.
xsgabs models A multiplicative gaussian absorption line. XSPEC model.
xsgadem models Plasma emission, multi-temperature with gaussian distribution of emission measure. XSPEC model.
xsgaussian models Simple gaussian line profile. XSPEC model.
xsgnei models Generalized single ionization NEI plasma model. XSPEC model.
xsgrad models GR accretion disk around a black hole. XSPEC model.
xsgrbm models Gamma-ray burst model. XSPEC model.
xsheilin models Voigt absorption profiles for He I series. XSPEC model.
xshighecut models High energy cutoff. XSPEC model.
xshrefl models Simple reflection model good up to 15 keV. XSPEC model.
xskerrbb models Multi-temperature blackbody model for thin accretion disk around a Kerr black hole. XSPEC model.
xskerrdisk models Accretion disk line emission with BH spin as free parameter. XSPEC model.
xskerrd models Optically thick accretion disk around a Kerr black hole. XSPEC model.
xslaor2 models Accretion disk with broken-power law emissivity profile, black hole emission line. XSPEC model.
xslaor models Line from accretion disk around a black hole. XSPEC model.
xslogpar models Log-parabolic blazar model. XSPEC model.
xslorentz models Lorentzian line profile. XSPEC model.
xslyman models Voigt absorption profiles for H I or He II Lyman series XSPEC model.
xsmekal models Mewe-Kaastra-Liedahl thermal plasma (1995). XSPEC model.
xsmeka models Mewe-Gronenschild-Kaastra thermal plasma (1992). XSPEC model.
xsmkcflow models Cooling flow model based on mekal. XSPEC model.
xsnei models Simple nonequilibrium ionization plasma model. XSPEC model.
xsnotch models Notch line absorption. XSPEC model.
xsnpshock models Plane-parallel shock with ion and electron temperatures. XSPEC model.
xsnsagrav models NS H atmosphere model for different g. XSPEC model.
xsnsatmos models NS Hydrogen Atmosphere model with electron conduction and self-irradiation. XSPEC model.
xsnsa models Spectra in the X-ray range (0.05-10 keV) emitted from a hydrogen atmosphere of a neutron star. XSPEC model.
xsnsmaxg models Neutron star with a magnetic atmosphere. XSPEC model.
xsnsmax models Neutron Star Magnetic Atmosphere. XSPEC model.
xsnsx models Neutron Star with a non-magnetic atmosphere. XSPEC model.
xsnteea models Pair plasma model. XSPEC model.
xsnthcomp models Thermally comptonized continuum. XSPEC model.
xsoptxagnf models Color-temperature-corrected disc and energetically coupled Comptonization model for AGN. XSPEC model.
xsoptxagn models Color-temperature-corrected disc and energetically coupled Comptonization model for AGN. XSPEC model.
xspcfabs models Partial covering fraction absorption. XSPEC model.
xspegpwrlw models Power law with pegged normalization. XSPEC model.
xspexmon models Neutral Compton reflection with self-consistent Fe and Ni lines. XSPEC model.
xspexrav models Exponentially cutoff power law reflected from neutral matter. XSPEC model.
xspexriv models Exponentially cutoff power law reflected from ionized matter. XSPEC model.
xsphabs models Photo-electric absorption. XSPEC model.
xsplabs models Absorption model with power law dependence on energy. XSPEC model.
xsplcabs models Cutoff power law observed through dense, cold matter. XSPEC model.
xsposm models Positronium continuum. XSPEC model.
xspowerlaw models Simple photon power law. XSPEC model.
xspshock models Constant temperature, plane-parallel shock plasma model. XSPEC model.
xspwab models An extension of partial covering fraction absorption into a power-law distribution of covering fraction. XSPEC model.
xsraymond models Raymond-Smith thermal plasma. XSPEC model.
xsredden models IR/optical/UV extinction from Cardelli et al. (1989). XSPEC model.
xsredge models Recombination edge. XSPEC model.
xsrefsch models E-folded power law reflected from an ionized relativistic disk. XSPEC model.
xsrnei models Non-equilibrium recombining collisional plasma model. XSPEC model.
xssedov models Sedov model with electron and ion temperatures. XSPEC model.
xssirf models Self-irradiated funnel. XSPEC model.
xssmedge models Smoothed absorption edge. XSPEC model.
xsspexpcut models Super-exponential cutoff absorption. XSPEC model.
xsspline models Spline multiplicative factor. XSPEC model.
xssrcut models Synchrotron radiation from cutoff electron distribution. XSPEC model.
xssresc models Synchrotron radiation from escape-limited electron distribution. XSPEC model.
xssss_ice models Einstein SSS ice absorption. XSPEC model.
xsstep models Step function convolved with gaussian. XSPEC model.
xsswind1 models Absorption by partially ionized material with large velocity shear. XSPEC model.
xstbabs models Calculates the absorption of X-rays by the ISM. XSPEC model.
xstbgrain models Calculates the absorption of X-rays by the ISM with variable hydrogen to H2 ratio and grain parameters. XSPEC model.
xstbvarabs models Calculates the absorption of X-rays by the ISM, allowing user to vary all abundances, depletion factors, and grain properties. XSPEC model.
xsuvred models UV reddening. XSPEC model.
xsvapec models APEC thermal plasma model with variable abundances. XSPEC model.
xsvarabs models Photoelectric absorption with variable abundances. XSPEC model.
xsvbremss models Thermal bremsstrahlung spectrum with variable H/He. XSPEC model.
xsvequil models Ionization equilibrium collisional plasma model with variable abundances. XSPEC model.
xsvgadem models Plasma emission, multi-temperature with gaussian distribution of emission measure. XSPEC model.
xsvgnei models Non-equilibrium ionization collisional plasma model with variable abundances. XSPEC model.
xsvmcflow models Cooling flow model based on vmekal. XSPEC model.
xsvmekal models Mewe-Kaastra-Liedahl thermal plasma with variable abundances. XSPEC model.
xsvmeka models Mewe-Gronenschild-Kaastra thermal plasma with variable abundances. XSPEC model.
xsvnei models Non-equilibrium ionization collisional plasma model with variable abundances. XSPEC model.
xsvnpshock models Plane-parallel shock plasma model with separate ion and electron temperatures and variable abundances. XSPEC model.
xsvphabs models Photoelectric absorption with variable abundances. XSPEC model.
xsvpshock models Constant temperature, plane-parallel shock plasma model with variable abundances. XSPEC model.
xsvraymond models Raymond-Smith thermal plasma with variable abundances. XSPEC model.
xsvrnei models Non-equilibrium recombining collisional plasma model with variable abundances. XSPEC model.
xsvsedov models Sedov model with separate ion and electron temperatures and variable abundances. XSPEC model.
xsvvapec models APEC thermal plasma model with variable abundances. XSPEC model.
xsvvgnei models Non-equilibrium ionization collisional plasma model with variable abundances for all elements with Z <= 30. XSPEC model.
xsvvnei models Non-equilibrium ionization collisional plasma model with variable abundances for all elements with Z <= 30. XSPEC model.
xsvvnpshock models Plane-parallel shock plasma model with separate ion and electron temperatures and variable abundances for all elements with Z <= 30. XSPEC model.
xsvvpshock models Constant temperature, plane-parallel shock plasma model with variable abundances for all elements with Z <= 30. XSPEC model.
xsvvrnei models Non-equilibrium recombining collisional plasma model with variable abundances for all elements with Z <= 30. XSPEC model.
xsvvsedov models Sedov model with separate ion and electron temperatures and variable abundances for all elements with Z <= 30. XSPEC model.
xswabs models Photoelectric absorption (Morrison and McCammon). XSPEC model.
xswndabs models Photoelectric absorption with low energy window. XSPEC model.
xsxion models Reflected spectra of a photo-ionized accretion disk or ring. XSPEC model.
xszagauss models Redshifted gaussian line profile in wavelength space. XSPEC model.
xszbabs models EUV ISM attenuation XSPEC model.
xszbbody models Redshifted blackbody. XSPEC model.
xszbremss models Redshifted thermal bremsstrahlung. XSPEC model.
xszdust models Extinction by dust grains. XSPEC model.
xszedge models Redshifted absorption edge. XSPEC model.
xszgauss models Redshifted gaussian. XSPEC model.
xszhighect models Redshifted high energy cutoff. XSPEC model.
xszigm models UV/Optical attenuation by the intergalactic medium.
xszpcfabs models Redshifted partial covering absorption. XSPEC model.
xszphabs models Redshifted photoelectric absorption. XSPEC model.
xszpowerlw models Redshifted power law. XSPEC model.
xszredden models Redshifted version of redden. XSPEC model.
xszsmdust models Extinction by dust grains in starburst galaxies. XSPEC model.
xsztbabs models Calculates the absorption of X-rays by the ISM for modeling redshifted absorption. Does not include a dust component. XSPEC model.
xszvarabs models Redshifted photoelectric absorption with variable abundances. XSPEC model.
xszvfeabs models Redshifted photoelectric absorption with free Fe edge energy. XSPEC model.
xszvphabs models Redshifted photoelectric absorption with variable abundances. XSPEC model.
xszwabs models Redshifted "Wisconsin absorption." XSPEC model.
xszwndabs models Redshifted photoelectric absorption with low energy window. XSPEC model.
xszxipcf models Partial covering absorption by partially ionized material. XSPEC model.
xs models XSPEC model functions.

Last modified: 15 December 2016
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