build.model: Build a model for a galaxy spectrum from a stellar template...

In oczoske/slacR: R-package to measure v and sigma from VIMOS IFU cubes

Description

This function convolves a stellar template spectrum with a Gaussian or Gauss-Hermite LOSVD and adjusts the continuum with additive and a multiplicative polynomial corrections to match a galaxy spectrum.

Usage

build.model(x, y, p,  LOSVD=c("gauss", "gh", "gauss-hermite", "shift"),
            o.mult = 4, o.add = 6, p.mult=NULL, p.add=NULL)

Arguments

x	an object of class spectrum. This should be a high-resolution stellar template spectrum.
y	an object of class spectrum. This should be a galaxy spectrum
p	a four-component vector containing the parameters for the template fit: velocity v and velocity dispersion sigma, both in km/s, h3 and h4.
LOSVD	Shape of the LOSVD to be fit to the spectrum. Defaults to Gaussian but can also be set to a Gauss-Hermite series, to order 4.
o.mult	order of polynomial multiplying the convolved template spectrum
o.add	order of polynomial added to the convolved template spectrum
p.mult, p.add	polynomials over y$lambda. These are created with poly with an additional first column of 1.

Details

The resulting model spectrum is resampled to the galaxy vector, y$lambda. The coefficients of the multiplicative and additive polynomials are determined from a linear fit of the model spectrum to the galaxy spectrum for fixed parameters p. The model will typically be used by merit.function to compute the goodness of fit for the given kinematic parameters.

Value

an object of class kinfit (inheriting from spectrum) with the convolved and continuum adjusted model spectrum resampled to the wavelength vector of the galaxy spectrum, the residuals, and all the parameters going into building the model

Author(s)

Oliver Czoske

References

D. Kelson et al. 2000, ApJ 531, 159

See Also

merit.function, fit.spectrum

oczoske/slacR documentation built on May 20, 2019, 8:23 p.m.