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Last modified: 28 October 2009

Fitting


Sherpa provides extensive facilities for modeling and fitting data. The topics here range from basic fits using source spectra and responses to more advanced areas, such as simultaneous fits to multiple data sets, accounting for the effects of pileup, and fitting spatial and grating data.

Before fitting ACIS spectral data sets with limited pulse-height ranges, please read the CIAO caveat "Spectral analyses of ACIS data with a limited pulse-height range."

  • Spectral (1-D) Data

    • Introduction to Fitting PHA Spectra (S-Lang or Python)
    • Changing the grouping scheme of a data set within Sherpa (S-Lang or Python)
    • Introduction to Fitting ASCII Data with Errors: Single-Component Source Models (S-Lang or Python)
    • Simultaneously Fitting Two Data Sets (S-Lang or Python)
    • Simulating 1-D Data: the Sherpa FAKE_PHA Command (S-Lang or Python)
    • Simulating Chandra ACIS-S Spectra with Sherpa (S-Lang or Python)
    • Fitting PHA Data with Multi-Component Source Models (S-Lang or Python)
    • Calculating Uncertainties by Simulating Flux Distributions (S-Lang or Python)
    • Independent Background Responses (S-Lang or Python)
    • Using A Pileup Model (S-Lang or Python)
    • Sherpa User Models (S-Lang or Python)
    • Sherpa Table Models (S-Lang or Python)
  • Spatial (2-D) Data

  • Grating Data

    Users interested in conducting wavelength analysis are encouraged to learn the limitations associated with the set_analysis command (S-Lang or Python help) before doing so with the information contained in these threads.

    • Fitting Grating Data (S-Lang or Python)
    • Fitting Multiple Orders of HRC-S/LETG Data (S-Lang or Python)
    • Measuring Line Parameters with an HETG/ACIS-S Spectrum (S-Lang or Python)
    • Measuring Line Parameters with an LETG/ACIS-S Spectrum (S-Lang or Python)
  • Generic Data

    These threads involve data analysis which is not specific to X-ray spectral or spatial modeling, therefore they can be followed using simple ASCII files as input, or other non-X-ray data.

    • Introduction to Fitting ASCII Data with Errors: Single-Component Source Models (S-Lang or Python)
    • CIAO thread: Obtain and Fit a Radial Profile (S-Lang or Python)
    • Sherpa User Models (S-Lang or Python)
    • Sherpa Table Models (S-Lang or Python)
Last modified: 28 October 2009


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