fit.cube: Function to perform kinematic analysis over a VIMOS IFU data...

Description Usage Arguments Details Value Author(s) See Also

Description

This function is a wrapper function, it calls fit.spectrum for every spectrum in a VIMOS IFU data cube.

Usage

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fit.cube(config, galspec, template, LOSVD=c("gauss", "gh",
         "gauss-hermite"), mask, output, errors = 0, SN.lim = 8, 
         dv = 25, verbose = TRUE, sigma.max = 1000, normalize = FALSE,
         ...)

Arguments

config

name of a file or list containing relevant data on the object on which the kinematic analysis is to be performed

galspec

(optional) a list of galaxy spectra, all on the same wavelength vector. This would be read in from a VIMOS cube with prepare.cube. If missing, the name of the data cube is taken from config

template

(optional) an object of class spectrum containing the stellar template spectrum. If missing, the name of the template file is taken from config

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.

mask

a data.frame with two columns x1 and x2 giving the left and right limits of wavelength regions that are to be masked; or, the name of a file containing such a data.frame; or, a logical vector along galaxy$lambda, with TRUE for pixels that shall be included in the fit

output

the name of a file to which the resulting fit will be written by write.table

errors

Number of Monte Carlo simulations that will be performed for each spectrum in the cube to give an estimate of the error distribution; defaults to zero

SN.lim

Only spectra in the cube which have a signal-to-noise ratio larger than this value will be analysed by fit.spectrum. All others will have NA in their results

dv

velocity step on which the template spectrum will be initially sampled; defaults to 25 km/sec

verbose

logical. If TRUE, informative messages will be printed

sigma.max

Maximum allowed value for the velocity dispersion, defaults to 1000 km/s. This gives in principle a constrained optimization, although the best fit should not be affected.

normalize

Normalization factor for the data cube, defaults to FALSE, i.e. no normalization at all

...

Further parameters to be passed to fit.spectrum. These would be in particular niter, nsig and plot.

Details

Beware of running too many error realizations, this takes a hell of a long time.

Value

An object of class kinmap obtained from fit.spectrum with simple=TRUE. If output is given, the result will be written directly to a file in the form of a data.frame.

v, sig, gof, h3, h4

The best fitting values for velocity and velocity dispersion, and the corresponding value of the merit.function

v1, v2

first and second velocity moments of the best-fitting LOSVD

dv.low, dv.high, dsig.low, dsig.high,...

If errors is larger than zero, 68% confidence limits for velocity and velocity dispersion and other parameters

SN, level, noise

The signal-to-noise, level and noise for the galaxy spectrum.

rms

The root-mean-square residuals of the best fit; this can be compared to noise

L, M

coordinates of the fibre in the data cube

template, sptype, FeH, logg, Teff

some data on the template used

Author(s)

Oliver Czoske

See Also

fit.spectrum


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