Spectral templates

This page describes the spectral templates used by the gwynz photometric redshift program.
The basis of the template set are the Coleman, Wu and Weedman (1980) spectra. These are suplemented with the SB2 and SB3 spectra from Kinney et al. (1996) .

All these spectra have been extrapolated slightly into the UV. For the purposes of photometric redshifts, it has been found that the exact nature of this extrapolation is unimportant: the size of the Lyman break imposed on the spectra of high redshift galaxies by the IGM makes the exact shape of the underlying galaxy spectrum almost irrelevant.

Having only a small number of templates can cause aliasing in photometric redshifts. Therefore, new templates have been created by interpolating between each of the six original templates. There are a total of 51 templates, as shown below.

The figure at right shows the template spectra. The bold lines are the the spectra from Coleman, Wu and Weedman and Kinney at al., (as labelled). The light lines are the interpolated spectra.
These templates are available in a tarball: or as individual files:

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