lte-codes	sterne	spectrum	ffit	sfit	grids	idlines
commands			ffit

FFIT

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Solves for T, theta, E(B-V) for one or two stars by fitting theoretical flux distributions to observed fluxes and/or photometry.

Input file structure:

command
or
command{  subcommand [ subcommand [ parameter [...]]] }
or
command subcommand [ subcommand [ parameter [...]]] end_command
 

• In general lines can be broken anywhere, but there are some exceptions.
• Strings beginning ! are treated as comments and ignored.
• Some commands can be broken up and/or placed in any order, but others (models and wavelength) must appear in order at the start of the input.

Command Summary

models	sets up model spectrum grid
wavelength	adjusts model wavelength grid
parameters	initialize spectrum fit parameters
method	select solution method
data	input observational data
solve	pursue solution by interpolation in grid
end	finish gracefully

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Example 1. Fit Teff, theta and E(B-V) to IUE spectrum and uvby photometry using a grid of helium-rich model flux distributions.

models{ 2 t01980001 Helium-rich constant g 11 1 1 0 0 0 /simon/models/01980001/19325he90L.s /simon/models/01980001/20325he90L.s /simon/models/01980001/21325he90L.s /simon/models/01980001/22325he90L.s /simon/models/01980001/23325he90L.s /simon/models/01980001/24325he90L.s /simon/models/01980001/25325he90L.s /simon/models/01980001/26325he90L.s /simon/models/01980001/27325he90L.s /simon/models/01980001/28325he90L.s }	!---! define model spectrum grid ! file format specifier ! grid title ! grid dimensions ! grid wavelength (use defaults) ! grid filenames
wavelengths{ iue phot 4 uvby }	!---! define photmetric system ! use standard IUE wavelength range ! use Stromgren magnitudes
parameters{ 3 20.0 1.0 'Teff kK' 0.03 0.01 'Ebv' 3.0E-11 0.5E-11 'theta' }
data{ folder . iue 059x.sp2 phot 10.487 10.516 10.501 10.559 errors 0.03 0.03 0.03 0.001 }	!---! read spectrum to fit ! data in current folder ! IUE data file in "spectrum format 2" ! uvby magnitudes ! uvby errors (in mag.)
solve end	! compute a solution

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This page is maintained by:
Simon Jeffery (csj@star.arm.ac.uk)
Last modified: 06/06/01