Fit function components

Introduction

This page lists the fit function components the user may select when doing a RHESSI spectral fit. The are chosen from the drop down menu at the top of the 'Choose Fit Function Components and Set Parameters' GUI:

The Fit Function Setup with components chosen and starting parameters adjusted

A simple tutorial on fitting a time interval using OSPEX can be found in OSPEX Documentation.

List of Available Fit Function Components

• vth - Variable Thermal
• vth_abun - Variable Thermal, Separate Abundances
• multi_therm_exp - Multithermal, Exp Temp
• multi_therm_abun_exp - Multithermal, Exp Temp, Separate Abundances
• multi_therm_pow - Multithermal, Pow Temp
• multi_therm_abun_pow - Multithermal, Pow Temp, Separate Abundances
• bpow - Broken Power Law
• 3pow - Triple Power Law
• line - Gaussian
• thin - Thin Target Bremsstrahlung
• thick - Thick Target Bremsstrahlung
• thick2 - Thick Target Bremsstrahlung Version 2
• ion - Non-uniform Target Ionization Spectrum
• drm_mod - Pseudo function for fine tuning RHESSI DRM parameters
• gain_mod - Pseudo function for modifying energy bins in model
• pileup_mod - Pseudo function for correcting pileup
• template - Template function
• positronium - Positronium + 511
• photon_thin - Thin Target photon Spectrum using Bethe-Heitler cross-section
• photon_thick - Thick target photon spectrum using Bethe-Heitler cross-section
• thin-kappa - thin_target bremsstrahlung spectrum for electron kappa distribution